Harnessing Plateau–Rayleigh Instability in GeS Nanowires for Nanoscale Optoelectronic Heterojunctions
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Harnessing Plateau–Rayleigh Instability in GeS Nanowires for Nanoscale Optoelectronic Heterojunctions
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  • Seong Bin Park
    Seong Bin Park
    Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Republic of Korea
    Program in Energy Process Innovation Convergence, Inha University, Incheon 22212, Republic of Korea
    More by Seong Bin Park
  • Yujin Kong
    Yujin Kong
    Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Republic of Korea
    Program in Energy Process Innovation Convergence, Inha University, Incheon 22212, Republic of Korea
    More by Yujin Kong
    Orcidhttps://orcid.org/0009-0004-9947-2725
  • Yu Chan Won
    Yu Chan Won
    Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Republic of Korea
    Program in Energy Process Innovation Convergence, Inha University, Incheon 22212, Republic of Korea
    More by Yu Chan Won
  • Naechul Shin*
    Naechul Shin
    Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Republic of Korea
    Program in Energy Process Innovation Convergence, Inha University, Incheon 22212, Republic of Korea
    Department of Chemical Engineering, Inha University, Incheon 22212, Republic of Korea
    *Email: [email protected]
    More by Naechul Shin
    Orcidhttps://orcid.org/0000-0002-2630-6820
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Nano Letters

Cite this: Nano Lett. 2025, 25, 45, 16219–16226
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https://doi.org/10.1021/acs.nanolett.5c04385
Published October 31, 2025

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Abstract

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Periodic shell formation in one-dimensional structures is a classical outcome of the Plateau–Rayleigh (P-R) instability, yet its manifestation in van der Waals (vdW) crystals has remained unexplored. Here, we demonstrate P-R instability in GeS vdW nanowires, synthesized by vapor–liquid–solid growth. Under elevated temperatures and continuous precursor supply, GeS nanowires transition from smooth sidewalls to periodic core–shell architectures. A quasi-liquid amorphous surface layer reorganizes into sulfur-rich shells surrounding a crystalline core. By tuning growth duration, both shell diameters and intershell pitches can be systematically controlled, consistent with theoretical predictions. Furthermore, these nanowires define site-specific nanoscale junctions in mixed-dimensional heterostructures. When integrated with monolayer WSe2, GeS shells create localized heterojunctions that drive charge transfer and excitonic modulation. Photoluminescence mapping and spectral analysis reveal exciton redshifts, trion enhancement, and localized quenching. These findings extend P-R instability to vdW materials and establish periodic nanowires as a platform for optoelectronic patterning.

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Periodic shell formation in cylindrical bodies is a classical manifestation of the Plateau–Rayleigh (P-R) instability, where a liquid column undergoes spontaneous breakup into droplets to minimize surface energy. (1,2) This principle has been widely observed not only in macroscopic liquid jets (3,4) but also in nanoscale systems such as one-dimensional (1D) nanowires, (5−8) where surface diffusion or liquid-mediated processes drive the evolution into modulated or discrete structures. These studies highlight the universality of P-R instability across different material classes and length scales, establishing it as an effective mechanism for nanoscale morphological transformation, particularly for creating diameter-modulated structures. Once controlled, such periodic modulation provides opportunities to tune physical properties along nanowires, including photonic response, excitonic recombination, electronic transport, and thermal conduction. (9−14)
P-R instability has been reported in nanowires composed of covalent semiconductors (5,6,15) and ionic compounds (8) (Table S1). Day et al. (5,6) reported periodic core–shell cubic Si/Ge nanowires driven by surface adatom diffusion during P-R crystal growth. Similarly, diameter oscillations in wurtzite InP nanowires (15) have been reported via an instability-driven periodic transition in the growth mode. More recently, P-R instability was demonstrated in a soft-lattice ionic material, Ag2S on a 1D Co9S8 nanowire. (8) Nonetheless, its realization in highly anisotropic, layered van der Waals (vdW) nanowires has remained unexplored. The strong crystalline anisotropy of vdW materials presents unique challenges: once confined into a 1D framework, their physical properties, especially the thermoelectric and optoelectronic behaviors, can be substantially modified depending on stacking orientation. (16−18) Furthermore, unlike conventional 3D semiconductors, interfacing 1D nanowires, including those made from vdW materials, with 2D semiconductors enables property modulation through distinct interfacial atomic arrangements at the heterojunction. (19−22) Thus, whether P-R instability can operate in vdW nanowires remains an open question, with the potential to generate unique structural signatures and functionalities not previously explored.
Here, we demonstrate that P-R instability can indeed occur in a vdW nanowire system, using germanium monosulfides (GeS) as a model platform. By conducting vapor–liquid–solid (VLS) growth at elevated temperature for short durations, we show that the intrinsic anisotropy of orthorhombic GeS provides a distinct pathway to instability with the GeS layers transversely stacked along the growth axis. The continuous exposure of edge facets promotes the formation of quasi-liquid amorphous surface layers with sufficient mobility to undergo P-R breakup, yielding a crystalline GeS core periodically modulated by amorphous, S-rich shells. We show that shell diameters and intershell pitches are systematically controlled by growth durations. Furthermore, these periodic shells serve as nanoscale junction definers when integrated into mixed-dimensional heterostructures with WSe2 monolayers. These interfaces exhibit localized charge transfer and excitonic modulation, enabling deterministic imprinting of a periodic optoelectronic landscape. Our findings extend the universality of P-R instability to vdW materials and demonstrate its utility in engineering functional heterostructures.

Periodic Shell Formation on GeS Nanowires via P-R Instability

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Figure 1a illustrates the formation of a periodic core–shell structure from a VLS-grown GeS nanowire. Below the eutectic point (<358 °C), VLS growth dominates, yielding uniform GeS 1D nanowires with transversely stacked vdW layers. (23−25) At elevated temperatures, however, a liquid phase can emerge at the nanowire sidewalls, leading to the nucleation of spherical shells with periodic spacing to reduce the surface energy via P-R instability. (26,27) Without precursor supply, this process often results in complete breakup of the nanowire into the discrete islands. (7,28) By contrast, with continuous precursor delivery, the adatom diffusion dynamically competes with the instability, producing diameter-modulated nanowires.

Figure 1

Figure 1. Periodic shell formation on a GeS van der Waals nanowire via the Plateau–Rayleigh (P-R) instability. (a) Schematic illustration showing the formation of a periodic core–shell GeS nanowire from a VLS-grown straight nanowire, driven by the P-R instability at elevated temperature. Inset highlights orthorhombic GeS crystal structure where the vdW layers are transversely stacked relative to the axial direction. (b) SEM image of a straight GeS nanowire grown from an Au catalyst. The growth was conducted by nucleating at 380 °C for 3 min and elongating at 300 °C for 10 min. The pressure and Ar carrier gas flow rate were 20 Torr and 50 sccm, respectively. Scale bar, 1 μm. (c) SEM images showing the evolution of periodic core–shell structure. The growth was continued at 390 °C, under a pressure of 20 Torr and an Ar gas flow rate of 50 sccm, for growth times (tg) of 2–5 min (from left to right). Scale bars, 500 nm. (d) Magnified SEM plan views of GeS nanowires. Top left: A straight VLS nanowire with its growth front decorated with an Au catalytic droplet. Bottom left and Top right: Core–shell structures showing periodic shells at tg = 3 and 4 min, respectively. Bottom right: Discrete islands formed by the P-R instability at tg = 5 min. Scale bars, 200 nm.

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As a reference, Figure 1b presents a scanning electron microscopy (SEM) image of a representative VLS-grown GeS nanowire with uniform diameter, obtained by nucleation at 380 °C for 3 min followed by elongation at 300 °C for 10 min. The growth was initiated from the colloidal Au particles (d ≈ 100 nm) drop-cast onto a Si(100) substrate (Figure S1). Transmission electron microscopy (TEM) analysis confirms the vdW GeS layers are stacked transversely relative to the nanowire axis (Figure S2). (23) In this configuration, the vdW layer edges are radially exposed, while sidewalls exhibit smooth morphology with negligible diameter modulation.
In contrast, raising the growth temperature to 390 °C for short durations (tg = 2–5 min) induces periodic diameter modulation (Figure 1c). Two key features are observed: (i) spherical shells decorating the nanowire sidewalls, with shell density increasing over time, and (ii) a systematic reduction of nanowire diameter compared to reference VLS nanowires. This trend persists up to tg = 4 min, after which the nanowires undergo breakup: at tg = 5 min, only discrete islands remain, especially near the tips, defining the upper limit of the P-R instability growth window.
Figure 1d shows magnified SEM images of morphological evolution. While the reference nanowire displays smooth sidewalls with an Au tip catalyst, nanowires grown under P-R conditions exhibit periodic shell arrays whose size and morphology depend on instability kinetics (see below for details). At tg = 5 min, extended high-temperature exposure results in dissolution of the nanowire core and its transformation into a linear array of discrete islands, consistent with P-R instability breakup.

Structural Analysis of GeS Periodic Core–Shell Nanowires

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Structural characteristics of the GeS periodic core–shell nanowires were examined using TEM and energy-dispersive X-ray spectroscopy (EDS). A representative low-magnification TEM image (Figure 2a) shows a GeS nanowire grown at 390 °C for 3 min, exhibiting highly regular periodic shells along its axis. The enlarged TEM image (Figure 2d) highlights alternating shell segments and thinner core regions. Notably, the contrast difference within the shell segments demonstrates the core is embedded inside the shells, while the curved shell surface indicates the shell crystallinity resembles a glassy or amorphous phase. High-resolution TEM (HRTEM) analysis provides further insight into this crystalline–amorphous core–shell structure (Figure 2c and Figure S3a). The core exhibits well-resolved lattice fringes (0.53 nm spacing, corresponding to (002) planes of orthorhombic GeS), (29,30) confirming [001] axial alignment. In contrast, the shell region appears amorphous, suggesting a quasi-liquid layer promotes P-R instability-driven shell growth over epitaxial ordering. Notably, this amorphous shell is stabilized by temperature quenching, effectively freezing the quasi-liquid shells (Figure S3d). The corresponding selected-area electron diffraction (SAED) pattern (bottom left inset) shows sharp diffraction spots indexed to the GeS lattice (e.g., [001] and [1̅10]), validating the single-crystalline nature of the nanowire core. These observations confirm transverse vdW layer stacking relative to the c-axis, similar to VLS-grown nanowires with smooth sidewalls at lower temperature (Figure S2). (23)

Figure 2

Figure 2. Structural analysis of GeS periodic shell nanowires. (a) Bright-field TEM image of a GeS periodic shell nanowire (tg = 3 min). Scale bar, 500 nm. (b) Magnified TEM image of the region marked by the red square in (a). Scale bar, 200 nm. (c) High-resolution TEM image of the crystalline core and amorphous shell, corresponding to the area in the blue box region of the top-left inset. The image shows a lattice spacing of 0.53 nm and confirms the axial orientation is along the [001] direction. Bottom left inset: Corresponding SAED pattern from a [110] zone axis, validating the axial orientation along the c-axis. Scale bars, 10 nm (main image), 100 nm (top-left inset), and 100 nm–1. (d) EDS elemental mapping images of the GeS periodic shell nanowire. Scale bar, 500 nm.

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Elemental mapping by EDS (Figure 2d) reveals Ge, S, and Au distribution within the periodic shell nanowire. While Au is primarily localized near the tip region alongside both Ge and S, consistent with its role as the VLS catalyst, Au signals are also detected along the nanowire body, which suggests sidewall surface diffusion and supports the observed diameter reduction. Both Ge and S signals are distributed throughout the nanowire; however, S appears more prominent in shell regions relative to Ge (Figure S3e), suggesting that amorphous shells are sulfur-rich GeSx. (23) Importantly, compositional analysis indicates an overall Ge:S atomic ratio of 1:1.08 (Figure S4), confirming average stoichiometry remains near GeS despite S-rich shells. Furthermore, Raman spectroscopy performed on an individual periodic GeS nanowire reveals only the characteristic phonon modes (Ag and B1g) of crystalline GeS (Figure S5), (31−33) supporting that complete phase segregation into elemental sulfur is unlikely. Taken together, the observed core thinning, combined with periodic S-rich shell formation, suggests that a S-rich quasi-liquid phase emerges along sidewalls, evolving into periodic shells via P-R instability.

Morphological Evolution during P-R Growth

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Growth-mediated P-R instability induces time-dependent modulation of the GeS nanowire diameter. Figure 3a shows representative SEM images comparing a uniform VLS nanowire grown at 300 °C with periodic core–shell nanowires obtained after 2, 3, and 4 min of continued growth at 390 °C. Along with the core diameter (Dc) thinning between shells, implying catalyst size reduction and enhanced sidewall diffusion, (34,35) an increasing trend in shell density is observed. It is also noteworthy that while the shell diameters (Ds) gradually decrease, shell contact angles exhibit an increasing trend with growth durations, observed across multiple nanowires (Figures S6 and S7). These observations collectively indicate that continuous precursor supply under conditions favoring radial instability over axial elongation is pivotal for determining the final periodic geometry.

Figure 3

Figure 3. Time-dependent periodic shell formation on GeS nanowire sidewalls. (a) SEM images showing the morphological evolution of GeS nanowire. A VLS nanowire with straight and uniform sidewall grown at 300 °C, periodic core–shell structures after growth for 2, 3, and 4 min at 390 °C (top to bottom). Scale bars, 500 nm. (b) AFM height map (top) and corresponding axial line profile (bottom) of a representative periodic core–shell nanowire with tg = 3 min. The profile shows a periodic height modulation superimposed on a gradual decrease in the average height from base (left) to tip (right). Scale bar, 1 μm. (c) Statistical distribution of the shell pitch as a function of growth time. (d) Nanowire (core) diameter (Dc, left axis) and the shell-to-core diameter ratio (Ds/Dc, right axis) as a function of growth time. The inset illustrates the definitions of these parameters. (e) Experimentally measured correlation between shell pitch and shell diameter for different growth times. The data are overlaid with a theoretical model prediction, where the solid red line indicates the thermodynamic threshold for spontaneous periodic shell formation (ΔGs < 0) for Dc = 50 nm and Dw = 100 nm, where Dw is the fictitious diameter of a conformal shell. (f) Theoretical stability diagram derived from the model, showing the calculated instability threshold as a function of shell diameter and pitch for various core and fictitious conformal shell diameters.

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Atomic force microscopy (AFM) was employed to further confirm the shell periodicity observed in SEM (Figure 3b). The topographical height map and corresponding axial line profile of a representative sample (tg = 3 min) reveal a well-defined periodic modulation in the nanowire height along its axis, which corresponds to the shell thickness whose values well matches with apparent diameter differences measured from SEM images (Figure S8). Notably, while a regular sequence of shell and core segments is observed, the average nanowire diameter (Da) decreases gradually toward the growth front (right side) along the nanowire length (L), following the relation Da = 56–0.0028L. This observation further supports a reduction in the core diameter, accompanied by Au diffusion along the sidewalls (Figure 2d) and a decreased capacity for axial elongation of the nanowire. In parallel, a quasi-liquid layer emerges at the sidewalls and contributes to periodic shell formation via P-R instability.
The statistical distribution of the shell pitch further quantifies this evolution, showing a decrease in average pitch with increasing growth time (Figure 3c). While tg = 2 min yields an average shell pitch of 740.2 ± 84.8 nm, the value decreases to 389.1 ± 83.6 nm and 326.2 ± 71.4 nm for tg = 3 and 4 min, respectively. This trend contrasts with prior studies, which reported either pitch independence from growth time (5) or an increase with growth time. (8) We attribute this difference to the coexistence of a crystalline core with an amorphous, quasi-liquid shell during the growth under continuous precursor supply. Although further investigation is needed, the emergence of the quasi-liquid surface layer appears to depend on both sidewall amorphization and diffusive precursor supply from the substrate, particularly when the Au catalytic capacity for axial elongation is reduced. Consistent with this picture, the lower portions of P-R nanowires exhibit larger diameters than upper segments (Figure S9), implying greater radial material accumulation near the base: the resulting increase in shell volume shortens the effective diffusion length along the sidewalls and thereby reduces the pitch.
When comparing nanowire diameters, the measured Dc values (45–50 nm) are substantially smaller than those of VLS nanowire (∼100 nm, circular symbols in Figure 3d). Concurrently, the ratio of the shell diameter to the core diameter (Ds/Dc) decreases from 4.9 to 3.5 (square symbols), reflecting a redistribution of volume that regulates the shell diameter. This is further supported by the observed increase in the contact angle of spherical shells (Figure S7), indicating that dewetting is favored over conformal coverage on cylindrical sidewalls under the given growth conditions.
The relationship between the final geometric parameters (shell diameter and pitch) is direct compared with the underlying theoretical model governing instability. Figure 3e plots the experimentally measured correlation from samples grown for different durations. The data points are overlaid with a theoretically calculated thermodynamic threshold for spontaneous shell formation (solid red line), based on a fictitious cylindrical nanowire of 50 nm core diameter and 100 nm conformal-shell diameter (Dw), chosen to conserve the total volume relative to the periodic shells (Figure S10). The close agreement between experiment and theory validates the predicted diameter dependence of shell pitch, which can be systematically modulated through growth durations.
The theoretical stability diagram in Figure 3f further elucidates these relationships, illustrating how the instability threshold depends on the interplay between Dc and Dw. Comparing these geometric factors shows that the shell pitch decreases with increasing Dw, a kinetically driven effect associated with increased shell volume via precursor diffusion, at fixed Ds. In contrast, a decrease in Dc, arising from thermodynamic instability of the Au catalyst at elevated temperatures, reduces Ds values at fixed shell pitch. Our experiments show a concurrent decrease in both shell diameter and shell pitch with time, which both quantifies the morphological evolution and provides effective validation of the P-R instability model, demonstrating a degree of control over the final periodic geometry.

Localized Optoelectronic Modulation

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Spatially distinct shell formation via P-R instability in our study enables functional optoelectronic properties that differ from those of conventional 1D nanowires with uniform diameters, particularly in terms of the interfacial phenomena. As a proof-of-concept platform for engineering optoelectronic interfaces, a representative core–shell nanowire was transferred onto a monolayer WSe2 flake, creating a mixed-dimensional vdW heterostructure (Figure 4a). The 2D WSe2 domains were grown on a c-sapphire substrate via chemical vapor deposition (CVD) process mediated by salt precursors (see Supporting Information for details), (19,36−38) and GeS nanowires were mechanically transferred such that some shell segments made direct contact with the WSe2. Figure 4b presents a photoluminescence (PL) map at the GeS emission wavelength (λ = 580 nm). Independent PL measurements on separate core–shell GeS nanowires (Figure S11) exhibit a bulk-like broad emission centered near 650 nm from core-only segments, whereas shell segments show a slightly blue-shifted emission toward shorter wavelength (≤600 nm), consistent with S-rich GeSx shell. (23) The map reveals distinct intensity maxima localized at the shell segments (positions 1, 3, 5), whereas the thinner core-only regions (positions 2, 4, 6) exhibit weaker emission. This emission contrast directly reflects variations in local GeS volume and optical absorption cross-section induced by the periodic shell geometry. The resulting interface, where only the shell segments physically contact the underlying WSe2, forms an array of nanoscale heterojunctions, while the core-only regions remain partially suspended, minimizing interfacial coupling, as schematically illustrated in Figure 4c.

Figure 4

Figure 4. Spatially modulated optoelectronic properties of GeS/WSe2 mixed-dimensional vdW heterostructure. (a) OM image of a periodic core–shell GeS nanowire transferred onto a monolayer WSe2. Scale bar, 3 μm. (b) PL intensity map corresponding to the GeS emission (λ = 580 nm), showing emission is brightest at the shell segments (1, 3, 5). (c) Schematic illustration of the heterostructure, highlighting the direct vdW junctions formed between the GeS shells (i.e., 3, 5) and the underlying WSe2. (d) PL spectra from numbered nanowire points and a bare WSe2 region (black), showing broad GeS (λ ≤ 680 nm) and sharp WSe2 (∼750 nm) exciton peaks. Spectra are offset for clarity. (e) PL intensity map of the WSe2 emission (λ = 740 nm), confirming strong, localized PL quenching at the GeS shell junctions. Dashed circles indicate the locations of the spectra shown in (f). (f) Deconvoluted PL spectra from representative ‘Junction’ (top) and ‘Pristine’ (bottom) regions, as marked in (e). The peaks are fitted to a neutral exciton (X0) and a lower-energy trion (XT). The junction spectra exhibit a significant redshift (Δλ = 10 nm) and an enhanced trion contribution. (g) Spatially resolved hyperspectral maps along the nanowire axis, showing the direct correlation between the GeS PL intensity modulation and the redshift of the WSe2 PL at the shell junctions. Color scales are identical to those in (b) and (e). (h) Ratio of the integrated trion-to-exciton peak areas for junction segments located on the WSe2 flake, confirming a local enhancement of the trion population specifically at the shell junctions (3 and 5).

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PL spectra acquired at selected positions along the GeS nanowire (Figure 4d) exhibit two main features: (i) a broad GeS emission band centered at 580 nm and extending to beyond 680 nm, as confirmed by comparison with the pristine WSe2 spectrum (black), and (ii) a sharp WSe2 exciton emission near 750 nm (1.65 eV). With the exception of the positions 1 and 2, where the segment lies outside the junction, the WSe2 PL intensities are noticeably quenched at positions coinciding with the GeS shell-WSe2 junctions (positions 3 and 5) relative to the suspended core regions (positions 4 and 6) (Figure S12). This spatially localized effect is further corroborated by the WSe2 PL intensity map at λ = 740 nm (Figure 4e), which clearly shows suppressed emission at shell junction sites. It is noteworthy that, although flake edges typically exhibit strong PL emission, the shell junctions and their immediate surroundings display reduced intensity, suggesting that interfacial charge transfer occurs at these sites. (39)
Figure 4f presents spectral deconvolution of representative ‘Junction’ and ‘Pristine’ WSe2 regions. The junction spectra (shells 3 and 5) are characterized by a pronounced redshift (Δλ ≈ 10 nm) of the WSe2 exciton peak compared to the bare WSe2 corner (black dashed circle in Figure 4e) and edge regions (orange dashed circle in Figure 4e) located beneath suspended GeS segment. In addition, a significantly enhanced trion (XT, 1.575–1.593 eV) contribution relative to the neutral exciton (X0, 1.633–1.650 eV) is observed. The combination of exciton redshift and increased trion population indicates efficient interfacial charge transfer that results in local doping of the WSe2 monolayer. To determine the direction of this transfer, we conducted ultraviolet photoelectron spectroscopy (UPS) on the GeS nanowires (Figure S13). The measurements confirm a work function of 4.67 eV and a valence band maximum (VBM) located 0.33 eV below the Fermi level. Under Fermi level alignment, this results in a type-II band alignment at the GeS/WSe2 heterojunction. This configuration is consistent with our observations, wherein photogenerated electrons preferentially transfer into WSe2 while holes remain in GeS, thereby facilitating negative trion formation in WSe2 and causing PL redshift.
Hyperspectral PL line-scan mapping obtained along the nanowire axis (Figure 4g) reveals a clear correspondence between the periodic modulation of the GeS emission intensity and the spatially periodic redshift of the WSe2 PL. Compared to the core-only segments (positions 2, 4, 6), the GeS shell segments (positions 1, 3, 5) display pronounced emission bands in the range λ = 580 ∼ 660 nm, which directly correlate with changes in the local electronic environment of the WSe2 and promote trion formation under the type-II band alignment. Figure 4h demonstrates the local enhancement of the trion population, which plots the ratio of the integrated trion-to-exciton peak areas (XT/X0) obtained from the spectral deconvolution at the junction regions (Figure S14). This ratio exhibits local maxima at shell junctions (0.385 at position 3 and 0.448 at position 5) that are in direct contact with the WSe2 surface, confirming that interfacial charge transfer is significantly enhanced at these sites compared to the gapped intershell segments, which show lower ratio values (0.351 at position 4 and 0.374 at position 6). These findings highlight the contact-distance dependence of the heterojunction: charge transfer is highly efficient at points of intimate vdW contact but is substantially suppressed across even small gaps where the core segment is suspended. While our study focuses on imprinting a periodic electronic landscape onto a 2D semiconductor, the ability to control the shell geometry is critical for realizing novel device applications. This spatial modulation achieved through controlled shell dimeter, intershell pitch, and morphology (5,6,40,41) can be harnessed to create nanoscale arrays of optoelectronic components such as photodetectors, (42) site-controlled quantum emitters, (43) or optical phase modulators. (44)
In summary, we demonstrate P-R instability in a vdW GeS nanowire system and leverage it as a functional modulator in mixed-dimensional heterostructures. VLS growth at 390 °C for short durations (<5 min) produces a crystalline core-amorphous shell hybrid architecture whose shell diameter and pitch are systematically tunable within a thermodynamic stability window. Beyond morphology, when integrated with 2D monolayer WSe2, the periodic shells define nanoscale junctions that locally modulate excitonic response, producing site-specific PL quenching and ∼10 nm redshifts accompanied by a locally enhanced trion population. These findings extend the universality of P-R instability to vdW materials and establish periodic shell nanowires as a practical platform for spatially programmable optoelectronic and photonic devices.

Supporting Information

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The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.nanolett.5c04385.

  • SEM image of Au nanoparticles dispersed on Si substrate and optical microscopic images of as-grown and dry-transferred GeS nanowires. TEM and EDS analyses of straight and core–shell nanowires. EDS spectra of core–shell GeS nanowires. Raman spectrum of a periodic core–shell GeS nanowire. Additional SEM images of periodic core–shell GeS nanowires at different growth durations. Statistical distributions of shell diameters and shell contact angles as a function of growth time. Comparison of shell-thicknesses measurements by AFM and SEM. Shell and core diameter comparison between upper and lower segments. Comparison of core and shell diameters at the upper and lower segments in periodic nanowires. Schematic comparing periodic shell and conformal shell structures. PL measurements on a core–shell GeS nanowire. PL spectra comparison between shell contact and intershell regions. UPS analysis of GeS. Superimposed PL intensity maps at the GeS and WSe2 emission wavelengths. PL peak deconvolution near the GeS/WSe2 junction regions. Comparison of P-R instability in nanowires reported in previous studies. (PDF)

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Author Information

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  • Corresponding Author
    • Naechul Shin - Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Republic of Korea;  Program in Energy Process Innovation Convergence, Inha University, Incheon 22212, Republic of Korea;  Department of Chemical Engineering, Inha University, Incheon 22212, Republic of Korea;  Orcidhttps://orcid.org/0000-0002-2630-6820;  Email: [email protected]
  • Authors
    • Seong Bin Park - Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Republic of Korea;  Program in Energy Process Innovation Convergence, Inha University, Incheon 22212, Republic of Korea
    • Yujin Kong - Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Republic of Korea;  Program in Energy Process Innovation Convergence, Inha University, Incheon 22212, Republic of Korea;  Orcidhttps://orcid.org/0009-0004-9947-2725
    • Yu Chan Won - Program in Biomedical Science and Engineering, Inha University, Incheon 22212, Republic of Korea;  Program in Energy Process Innovation Convergence, Inha University, Incheon 22212, Republic of Korea
  • Author Contributions

    S.B.P. and Y.K. contributed to the materials and sample preparation. S.B.P. and Y.K. conducted GeS nanowire growth and sample analysis. Y.C.W. and Y.K. carried out WSe2 growth and PL measurements. S.B.P. and Y.K. analyzed the data and prepared the manuscript. N.S. supervised the project. All authors discussed the results and contributed to the manuscript writing. S.B.P. and Y.K. contributed equally.

  • Notes
    The authors declare no competing financial interest.

Acknowledgments

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This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (RS-2025-23525323). This work was also supported by Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea Government (MOTIE). (RS-2023-00243974, Graduate School of Digital-based Sustainable Energy Process Innovation Convergence).

References

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This article references 44 other publications.

  1. 1
    Eggers, J. Nonlinear dynamics and breakup of free-surface flows. Rev. Mod. Phys. 1997, 69 (3), 865,  DOI: 10.1103/RevModPhys.69.865
    Google Scholar
    There is no corresponding record for this reference.
  2. 2
    Barker, B.; Bell, J. B.; Garcia, A. L. Fluctuating hydrodynamics and the Rayleigh-Plateau instability. Proc. Natl. Acad. Sci. U. S. A. 2023, 120 (30), e2306088120  DOI: 10.1073/pnas.2306088120
    Google Scholar
    There is no corresponding record for this reference.
  3. 3
    Rayleigh, L. On The Instability Of Jets. Proc. London Math. Soc. 1878, s1–10 (1), 4– 13,  DOI: 10.1112/plms/s1-10.1.4
    Google Scholar
    There is no corresponding record for this reference.
  4. 4
    Eggers, J.; Villermaux, E. Physics of liquid jets. Rep. Prog. Phys. 2008, 71 (3), 036601  DOI: 10.1088/0034-4885/71/3/036601
    Google Scholar
    There is no corresponding record for this reference.
  5. 5
    Day, R. W.; Mankin, M. N.; Gao, R.; No, Y.-S.; Kim, S.-K.; Bell, D. C.; Park, H.-G.; Lieber, C. M. Plateau–Rayleigh crystal growth of periodic shells on one-dimensional substrates. Nat. Nanotechnol. 2015, 10 (4), 345– 352,  DOI: 10.1038/nnano.2015.23
    Google Scholar
    There is no corresponding record for this reference.
  6. 6
    Day, R. W.; Mankin, M. N.; Lieber, C. M. Plateau–Rayleigh Crystal Growth of Nanowire Heterostructures: Strain-Modified Surface Chemistry and Morphological Control in One, Two, and Three Dimensions. Nano Lett. 2016, 16 (4), 2830– 2836,  DOI: 10.1021/acs.nanolett.6b00629
    Google Scholar
    There is no corresponding record for this reference.
  7. 7
    Xue, Z.; Xu, M.; Zhao, Y.; Wang, J.; Jiang, X.; Yu, L.; Wang, J.; Xu, J.; Shi, Y.; Chen, K.; Roca i Cabarrocas, P. Engineering island-chain silicon nanowires via a droplet mediated Plateau–Rayleigh transformation. Nat. Commun. 2016, 7 (1), 12836,  DOI: 10.1038/ncomms12836
    Google Scholar
    There is no corresponding record for this reference.
  8. 8
    Shao, Z.-C.; Jiang, X.; Zhang, C.; Wang, T.; Wang, Y.-R.; Liu, G.-Q.; Huang, Z.-Y.; Zhang, Y.-Z.; Wu, L.; Hou, Z.-H. Plateau–Rayleigh Instability in Soft-Lattice Inorganic Solids. J. Am. Chem. Soc. 2024, 146 (49), 33774– 33783,  DOI: 10.1021/jacs.4c11866
    Google Scholar
    There is no corresponding record for this reference.
  9. 9
    Custer, J. P.; Low, J. D.; Hill, D. J.; Teitsworth, T. S.; Christesen, J. D.; McKinney, C. J.; McBride, J. R.; Brooke, M. A.; Warren, S. C.; Cahoon, J. F. Ratcheting quasi-ballistic electrons in silicon geometric diodes at room temperature. Science 2020, 368 (6487), 177– 180,  DOI: 10.1126/science.aay8663
    Google Scholar
    There is no corresponding record for this reference.
  10. 10
    White, K. L.; Umantsev, M. A.; Low, J. D.; Custer, J. P.; Cahoon, J. F. Influence of Geometry on Quasi-Ballistic Behavior in Silicon Nanowire Geometric Diodes. ACS Appl. Nano Mater. 2023, 6 (7), 5117– 5126,  DOI: 10.1021/acsanm.2c04666
    Google Scholar
    There is no corresponding record for this reference.
  11. 11
    White, K. L.; Rogelberg, G. V.; Custer, J. P.; Cahoon, J. F. Omega-Gate Silicon Nanowire Geometric Diodes with Reconfigurable Self-Switching Operation and THz Rectification. Adv. Electron. Mater. 2024, 10 (1), 2300466  DOI: 10.1002/aelm.202300466
    Google Scholar
    There is no corresponding record for this reference.
  12. 12
    Malhotra, A.; Tutuncuoglu, G.; Kommandur, S.; Creamer, P.; Rajan, A.; Mohabir, A.; Yee, S.; Filler, M. A.; Maldovan, M. Impact of Porosity and Boundary Scattering on Thermal Transport in Diameter-Modulated Nanowires. ACS Appl. Mater. Interfaces 2022, 14 (1), 1740– 1746,  DOI: 10.1021/acsami.1c20242
    Google Scholar
    There is no corresponding record for this reference.
  13. 13
    Blandre, E.; Chaput, L.; Merabia, S.; Lacroix, D.; Termentzidis, K. Modeling the reduction of thermal conductivity in core/shell and diameter-modulated silicon nanowires. Phys. Rev. B 2015, 91 (11), 115404  DOI: 10.1103/PhysRevB.91.115404
    Google Scholar
    There is no corresponding record for this reference.
  14. 14
    Ko, M.; Baek, S. H.; Song, B.; Kang, J. W.; Kim, S. A.; Cho, C. H. Periodically Diameter-Modulated Semiconductor Nanowires for Enhanced Optical Absorption. Adv. Mater. 2016, 28 (13), 2504– 2510,  DOI: 10.1002/adma.201505144
    Google Scholar
    There is no corresponding record for this reference.
  15. 15
    Oliveira, D. S.; Tizei, L. H. G.; Ugarte, D.; Cotta, M. A. Spontaneous Periodic Diameter Oscillations in InP Nanowires: The Role of Interface Instabilities. Nano Lett. 2013, 13 (1), 9– 13,  DOI: 10.1021/nl302891b
    Google Scholar
    There is no corresponding record for this reference.
  16. 16
    Sutter, P.; Sutter, E. Tunable 1D van der Waals Nanostructures by Vapor-Liquid-Solid Growth. Acc. Chem. Res. 2023, 56 (22), 3235– 3245,  DOI: 10.1021/acs.accounts.3c00502
    Google Scholar
    There is no corresponding record for this reference.
  17. 17
    Sutter, E.; Kisslinger, K.; Wu, L.; Zhu, Y.; Yang, S.; Camino, F.; Nam, C. Y.; Sutter, P. Single Crystalline GeSe Van Der Waals Ribbons With Uniform Layer Stacking, High Carrier Mobility, and Adjustable Edge Morphology. Small 2024, 20 (50), 2406129  DOI: 10.1002/smll.202406129
    Google Scholar
    There is no corresponding record for this reference.
  18. 18
    Liu, Y.; Jin, L.; Pandey, T.; Sun, H.; Liu, Y.; Li, X.; Rodriguez, A.; Wang, Y.; Zhou, T.; Chen, R. Anomalous thermal transport in Eshelby twisted van der Waals nanowires. Nat. Mater. 2025, 24 (5), 728– 734,  DOI: 10.1038/s41563-024-02108-3
    Google Scholar
    There is no corresponding record for this reference.
  19. 19
    Song, H.; Ji, S.; Kang, S. G.; Shin, N. Contact Geometry-Dependent Excitonic Emission in Mixed-Dimensional van der Waals Heterostructures. ACS Nano 2024, 18 (29), 19179– 19189,  DOI: 10.1021/acsnano.4c04770
    Google Scholar
    There is no corresponding record for this reference.
  20. 20
    Jiang, K.; You, Q.; Zheng, Y.; Fang, F.; Xie, Z.; Li, H.; Wan, Y.; Han, C.; Shi, Y. Oriented Epitaxial Growth of Mixed-Dimensional van der Waals Heterostructures with One-Dimensional (1D) Bi2S3 Nanowires and Two-Dimensional (2D) WS2 Monolayers for Performance-Enhanced Photodetectors. Nano Lett. 2024, 24 (45), 14437– 14444,  DOI: 10.1021/acs.nanolett.4c04455
    Google Scholar
    There is no corresponding record for this reference.
  21. 21
    Lv, Q.; Tan, J.; Wang, Z.; Gu, P.; Liu, H.; Yu, L.; Wei, Y.; Gan, L.; Liu, B.; Li, J.; Kang, F.; Cheng, H.-M.; Xiong, Q.; Lv, R. Ultrafast charge transfer in mixed-dimensional WO3-x nanowire/WSe2 heterostructures for attomolar-level molecular sensing. Nat. Commun. 2023, 14 (1), 2717,  DOI: 10.1038/s41467-023-38198-x
    Google Scholar
    There is no corresponding record for this reference.
  22. 22
    Yang, X.; Wu, R.; Zheng, B.; Luo, Z.; You, W.; Liu, H.; Li, L.; Zhang, Y.; Tan, Q.; Liang, D. A Waveguide-Integrated Two-Dimensional Light-Emitting Diode Based on p-Type WSe2/n-Type CdS Nanoribbon Heterojunction. ACS Nano 2022, 16 (3), 4371– 4378,  DOI: 10.1021/acsnano.1c10607
    Google Scholar
    There is no corresponding record for this reference.
  23. 23
    Sutter, E.; Sutter, P. 1D Wires of 2D Layered Materials: Germanium Sulfide Nanowires as Efficient Light Emitters. ACS Appl. Nano Mater. 2018, 1 (3), 1042– 1049,  DOI: 10.1021/acsanm.7b00053
    Google Scholar
    There is no corresponding record for this reference.
  24. 24
    Sutter, P.; Idrobo, J. C.; Sutter, E. Van der Waals Nanowires with Continuously Variable Interlayer Twist and Twist Homojunctions. Adv. Funct. Mater. 2021, 31 (9), 2006412  DOI: 10.1002/adfm.202006412
    Google Scholar
    There is no corresponding record for this reference.
  25. 25
    Sutter, E.; French, J. S.; Sutter, P. Tunable Layer Orientation and Morphology in Vapor–Liquid–Solid Growth of One-Dimensional GeS van der Waals Nanostructures. Chem. Mater. 2021, 33 (11), 3980– 3988,  DOI: 10.1021/acs.chemmater.1c00289
    Google Scholar
    There is no corresponding record for this reference.
  26. 26
    Dolado, J.; Renforth, K. L.; Nunn, J. E.; Hindsmarsh, S. A.; Hidalgo, P.; Sánchez, A. M.; Méndez, B. Zn2GeO4/SnO2 Nanowire Heterostructures Driven by Plateau–Rayleigh Instability. Cryst. Growth Des. 2020, 20 (1), 506– 513,  DOI: 10.1021/acs.cgd.9b01494
    Google Scholar
    There is no corresponding record for this reference.
  27. 27
    Mead-Hunter, R.; King, A. J.; Mullins, B. J. Plateau Rayleigh instability simulation. Langmuir 2012, 28 (17), 6731– 6735,  DOI: 10.1021/la300622h
    Google Scholar
    There is no corresponding record for this reference.
  28. 28
    Shabahang, S.; Kaufman, J. J.; Deng, D. S.; Abouraddy, A. F. Observation of the Plateau–Rayleigh capillary instability in multi-material optical fibers. Appl. Phys. Lett. 2011, 99 (16), 161909  DOI: 10.1063/1.3653247
    Google Scholar
    There is no corresponding record for this reference.
  29. 29
    Malone, B. D.; Kaxiras, E. Quasiparticle band structures and interface physics of SnS and GeS. Phys. Rev. B 2013, 87 (24), 245312  DOI: 10.1103/PhysRevB.87.245312
    Google Scholar
    There is no corresponding record for this reference.
  30. 30
    Li, C.; Yu, Y.; Chi, M.; Cao, L. Epitaxial Nanosheet-Nanowire Heterostructures. Nano Lett. 2013, 13 (3), 948– 953,  DOI: 10.1021/nl303876a
    Google Scholar
    There is no corresponding record for this reference.
  31. 31
    Ribeiro, H. B.; Ramos, S. L. L. M.; Seixas, L.; de Matos, C. J. S.; Pimenta, M. A. Edge phonons in layered orthorhombic GeS and GeSe monochalcogenides. Phys. Rev. B 2019, 100 (9), 094301  DOI: 10.1103/PhysRevB.100.094301
    Google Scholar
    There is no corresponding record for this reference.
  32. 32
    Hsueh, H. C.; Warren, M. C.; Vass, H.; Ackland, G. J.; Clark, S. J.; Crain, J. Vibrational properties of the layered semiconductor germanium sulfide under hydrostatic pressure: Theory and experiment. Phys. Rev. B 1996, 53 (22), 14806,  DOI: 10.1103/PhysRevB.53.14806
    Google Scholar
    There is no corresponding record for this reference.
  33. 33
    Jadczak, J.; Andrzejewski, J.; Debus, J.; Ho, C. H.; Bryja, L. Resonant Exciton Scattering Reveals Raman Forbidden Phonon Modes in Layered GeS. J. Phys. Chem. Lett. 2023, 14 (17), 3986– 3994,  DOI: 10.1021/acs.jpclett.3c00783
    Google Scholar
    There is no corresponding record for this reference.
  34. 34
    Dayeh, S. A.; Yu, E. T.; Wang, D. Surface Diffusion and Substrate-Nanowire Adatom Exchange in InAs Nanowire Growth. Nano Lett. 2009, 9 (5), 1967– 1972,  DOI: 10.1021/nl900191w
    Google Scholar
    There is no corresponding record for this reference.
  35. 35
    Dayeh, S. A.; Mack, N. H.; Huang, J. Y.; Picraux, S. T. Advanced core/multishell germanium/silicon nanowire heterostructures: The Au-diffusion bottleneck. Appl. Phys. Lett. 2011, 99 (2), 023102  DOI: 10.1063/1.3567932
    Google Scholar
    There is no corresponding record for this reference.
  36. 36
    Lee, Y.; Shin, N. Mechanistic insights into diffusion-controlled 2D WSe2 growth via chemical vapor deposition in confined spaces. FlatChem. 2025, 51, 100863  DOI: 10.1016/j.flatc.2025.100863
    Google Scholar
    There is no corresponding record for this reference.
  37. 37
    Suzuki, H.; Hashimoto, R.; Misawa, M.; Liu, Y.; Kishibuchi, M.; Ishimura, K.; Tsuruta, K.; Miyata, Y.; Hayashi, Y. Surface Diffusion-Limited Growth of Large and High-Quality Monolayer Transition Metal Dichalcogenides in Confined Space of Microreactor. ACS Nano 2022, 16 (7), 11360– 11373,  DOI: 10.1021/acsnano.2c05076
    Google Scholar
    There is no corresponding record for this reference.
  38. 38
    Li, S.; Hong, J.; Gao, B.; Lin, Y.-C.; Lim, H. E.; Lu, X.; Wu, J.; Liu, S.; Tateyama, Y.; Sakuma, Y.; Tsukagoshi, K.; Suenaga, K.; Taniguchi, T. Tunable Doping of Rhenium and Vanadium into Transition Metal Dichalcogenides for Two-Dimensional Electronics. Adv. Sci. 2021, 8 (11), 2004438  DOI: 10.1002/advs.202004438
    Google Scholar
    There is no corresponding record for this reference.
  39. 39
    Kim, J.; Jin, C.; Chen, B.; Cai, H.; Zhao, T.; Lee, P.; Kahn, S.; Watanabe, K.; Taniguchi, T.; Tongay, S.; Crommie, M. F.; Wang, F. Observation of ultralong valley lifetime in WSe2/MoS2 heterostructures. Sci. Adv. 2017, 3 (7), 1700518  DOI: 10.1126/sciadv.1700518
    Google Scholar
    There is no corresponding record for this reference.
  40. 40
    Musin, I. R.; Boyuk, D. S.; Filler, M. A. Surface chemistry controlled diameter-modulated semiconductor nanowire superstructures. J. Vac. Sci. Technol. B 2013, 31 (2), 020603  DOI: 10.1116/1.4792660
    Google Scholar
    There is no corresponding record for this reference.
  41. 41
    Christesen, J. D.; Pinion, C. W.; Hill, D. J.; Kim, S.; Cahoon, J. F. Chemically Engraving Semiconductor Nanowires: Using Three-Dimensional Nanoscale Morphology to Encode Functionality from the Bottom Up. J. Phys. Chem. Lett. 2016, 7 (4), 685– 692,  DOI: 10.1021/acs.jpclett.5b02444
    Google Scholar
    There is no corresponding record for this reference.
  42. 42
    Sharmila, B.; Dwivedi, P. MoS2/SiNWs heterostructure based repeatable and highly responsive photodetector. Opt. Mater. 2022, 133, 112918  DOI: 10.1016/j.optmat.2022.112918
    Google Scholar
    There is no corresponding record for this reference.
  43. 43
    Ananth, R.; Utama, M. I. B.; Xu, D. D.; Vong, A. F.; Sadhukhan, T.; Zeng, H.; López-Arteaga, R.; Wang, W.; Namgung, S. D.; Gavin, S. C. Enhanced spectral purity of WSe2 quantum emitters via conformal organic adlayers. Sci. Adv. 2025, 11 (40), eady7557  DOI: 10.1126/sciadv.ady7557
    Google Scholar
    There is no corresponding record for this reference.
  44. 44
    Wu, C.-H.; Reep, T.; Huang, Y.; Brems, S.; Haffner, C.; Huyghebaert, C.; Kuyken, B.; Van Campenhout, J.; Pantouvaki, M.; Van Thourhout, D. Low-loss phase modulation using a MoS2 monolayer integrated on silicon waveguides. 2D Mater. 2025, 12 (4), 045006  DOI: 10.1088/2053-1583/ade9d9
    Google Scholar
    There is no corresponding record for this reference.

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  • Abstract

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    Figure 1

    Figure 1. Periodic shell formation on a GeS van der Waals nanowire via the Plateau–Rayleigh (P-R) instability. (a) Schematic illustration showing the formation of a periodic core–shell GeS nanowire from a VLS-grown straight nanowire, driven by the P-R instability at elevated temperature. Inset highlights orthorhombic GeS crystal structure where the vdW layers are transversely stacked relative to the axial direction. (b) SEM image of a straight GeS nanowire grown from an Au catalyst. The growth was conducted by nucleating at 380 °C for 3 min and elongating at 300 °C for 10 min. The pressure and Ar carrier gas flow rate were 20 Torr and 50 sccm, respectively. Scale bar, 1 μm. (c) SEM images showing the evolution of periodic core–shell structure. The growth was continued at 390 °C, under a pressure of 20 Torr and an Ar gas flow rate of 50 sccm, for growth times (tg) of 2–5 min (from left to right). Scale bars, 500 nm. (d) Magnified SEM plan views of GeS nanowires. Top left: A straight VLS nanowire with its growth front decorated with an Au catalytic droplet. Bottom left and Top right: Core–shell structures showing periodic shells at tg = 3 and 4 min, respectively. Bottom right: Discrete islands formed by the P-R instability at tg = 5 min. Scale bars, 200 nm.

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    Figure 2

    Figure 2. Structural analysis of GeS periodic shell nanowires. (a) Bright-field TEM image of a GeS periodic shell nanowire (tg = 3 min). Scale bar, 500 nm. (b) Magnified TEM image of the region marked by the red square in (a). Scale bar, 200 nm. (c) High-resolution TEM image of the crystalline core and amorphous shell, corresponding to the area in the blue box region of the top-left inset. The image shows a lattice spacing of 0.53 nm and confirms the axial orientation is along the [001] direction. Bottom left inset: Corresponding SAED pattern from a [110] zone axis, validating the axial orientation along the c-axis. Scale bars, 10 nm (main image), 100 nm (top-left inset), and 100 nm–1. (d) EDS elemental mapping images of the GeS periodic shell nanowire. Scale bar, 500 nm.

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    Figure 3

    Figure 3. Time-dependent periodic shell formation on GeS nanowire sidewalls. (a) SEM images showing the morphological evolution of GeS nanowire. A VLS nanowire with straight and uniform sidewall grown at 300 °C, periodic core–shell structures after growth for 2, 3, and 4 min at 390 °C (top to bottom). Scale bars, 500 nm. (b) AFM height map (top) and corresponding axial line profile (bottom) of a representative periodic core–shell nanowire with tg = 3 min. The profile shows a periodic height modulation superimposed on a gradual decrease in the average height from base (left) to tip (right). Scale bar, 1 μm. (c) Statistical distribution of the shell pitch as a function of growth time. (d) Nanowire (core) diameter (Dc, left axis) and the shell-to-core diameter ratio (Ds/Dc, right axis) as a function of growth time. The inset illustrates the definitions of these parameters. (e) Experimentally measured correlation between shell pitch and shell diameter for different growth times. The data are overlaid with a theoretical model prediction, where the solid red line indicates the thermodynamic threshold for spontaneous periodic shell formation (ΔGs < 0) for Dc = 50 nm and Dw = 100 nm, where Dw is the fictitious diameter of a conformal shell. (f) Theoretical stability diagram derived from the model, showing the calculated instability threshold as a function of shell diameter and pitch for various core and fictitious conformal shell diameters.

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    Figure 4

    Figure 4. Spatially modulated optoelectronic properties of GeS/WSe2 mixed-dimensional vdW heterostructure. (a) OM image of a periodic core–shell GeS nanowire transferred onto a monolayer WSe2. Scale bar, 3 μm. (b) PL intensity map corresponding to the GeS emission (λ = 580 nm), showing emission is brightest at the shell segments (1, 3, 5). (c) Schematic illustration of the heterostructure, highlighting the direct vdW junctions formed between the GeS shells (i.e., 3, 5) and the underlying WSe2. (d) PL spectra from numbered nanowire points and a bare WSe2 region (black), showing broad GeS (λ ≤ 680 nm) and sharp WSe2 (∼750 nm) exciton peaks. Spectra are offset for clarity. (e) PL intensity map of the WSe2 emission (λ = 740 nm), confirming strong, localized PL quenching at the GeS shell junctions. Dashed circles indicate the locations of the spectra shown in (f). (f) Deconvoluted PL spectra from representative ‘Junction’ (top) and ‘Pristine’ (bottom) regions, as marked in (e). The peaks are fitted to a neutral exciton (X0) and a lower-energy trion (XT). The junction spectra exhibit a significant redshift (Δλ = 10 nm) and an enhanced trion contribution. (g) Spatially resolved hyperspectral maps along the nanowire axis, showing the direct correlation between the GeS PL intensity modulation and the redshift of the WSe2 PL at the shell junctions. Color scales are identical to those in (b) and (e). (h) Ratio of the integrated trion-to-exciton peak areas for junction segments located on the WSe2 flake, confirming a local enhancement of the trion population specifically at the shell junctions (3 and 5).

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  • References

    This article references 44 other publications.

    1. 1
      Eggers, J. Nonlinear dynamics and breakup of free-surface flows. Rev. Mod. Phys. 1997, 69 (3), 865,  DOI: 10.1103/RevModPhys.69.865
      There is no corresponding record for this reference.
    2. 2
      Barker, B.; Bell, J. B.; Garcia, A. L. Fluctuating hydrodynamics and the Rayleigh-Plateau instability. Proc. Natl. Acad. Sci. U. S. A. 2023, 120 (30), e2306088120  DOI: 10.1073/pnas.2306088120
      There is no corresponding record for this reference.
    3. 3
      Rayleigh, L. On The Instability Of Jets. Proc. London Math. Soc. 1878, s1–10 (1), 4– 13,  DOI: 10.1112/plms/s1-10.1.4
      There is no corresponding record for this reference.
    4. 4
      Eggers, J.; Villermaux, E. Physics of liquid jets. Rep. Prog. Phys. 2008, 71 (3), 036601  DOI: 10.1088/0034-4885/71/3/036601
      There is no corresponding record for this reference.
    5. 5
      Day, R. W.; Mankin, M. N.; Gao, R.; No, Y.-S.; Kim, S.-K.; Bell, D. C.; Park, H.-G.; Lieber, C. M. Plateau–Rayleigh crystal growth of periodic shells on one-dimensional substrates. Nat. Nanotechnol. 2015, 10 (4), 345– 352,  DOI: 10.1038/nnano.2015.23
      There is no corresponding record for this reference.
    6. 6
      Day, R. W.; Mankin, M. N.; Lieber, C. M. Plateau–Rayleigh Crystal Growth of Nanowire Heterostructures: Strain-Modified Surface Chemistry and Morphological Control in One, Two, and Three Dimensions. Nano Lett. 2016, 16 (4), 2830– 2836,  DOI: 10.1021/acs.nanolett.6b00629
      There is no corresponding record for this reference.
    7. 7
      Xue, Z.; Xu, M.; Zhao, Y.; Wang, J.; Jiang, X.; Yu, L.; Wang, J.; Xu, J.; Shi, Y.; Chen, K.; Roca i Cabarrocas, P. Engineering island-chain silicon nanowires via a droplet mediated Plateau–Rayleigh transformation. Nat. Commun. 2016, 7 (1), 12836,  DOI: 10.1038/ncomms12836
      There is no corresponding record for this reference.
    8. 8
      Shao, Z.-C.; Jiang, X.; Zhang, C.; Wang, T.; Wang, Y.-R.; Liu, G.-Q.; Huang, Z.-Y.; Zhang, Y.-Z.; Wu, L.; Hou, Z.-H. Plateau–Rayleigh Instability in Soft-Lattice Inorganic Solids. J. Am. Chem. Soc. 2024, 146 (49), 33774– 33783,  DOI: 10.1021/jacs.4c11866
      There is no corresponding record for this reference.
    9. 9
      Custer, J. P.; Low, J. D.; Hill, D. J.; Teitsworth, T. S.; Christesen, J. D.; McKinney, C. J.; McBride, J. R.; Brooke, M. A.; Warren, S. C.; Cahoon, J. F. Ratcheting quasi-ballistic electrons in silicon geometric diodes at room temperature. Science 2020, 368 (6487), 177– 180,  DOI: 10.1126/science.aay8663
      There is no corresponding record for this reference.
    10. 10
      White, K. L.; Umantsev, M. A.; Low, J. D.; Custer, J. P.; Cahoon, J. F. Influence of Geometry on Quasi-Ballistic Behavior in Silicon Nanowire Geometric Diodes. ACS Appl. Nano Mater. 2023, 6 (7), 5117– 5126,  DOI: 10.1021/acsanm.2c04666
      There is no corresponding record for this reference.
    11. 11
      White, K. L.; Rogelberg, G. V.; Custer, J. P.; Cahoon, J. F. Omega-Gate Silicon Nanowire Geometric Diodes with Reconfigurable Self-Switching Operation and THz Rectification. Adv. Electron. Mater. 2024, 10 (1), 2300466  DOI: 10.1002/aelm.202300466
      There is no corresponding record for this reference.
    12. 12
      Malhotra, A.; Tutuncuoglu, G.; Kommandur, S.; Creamer, P.; Rajan, A.; Mohabir, A.; Yee, S.; Filler, M. A.; Maldovan, M. Impact of Porosity and Boundary Scattering on Thermal Transport in Diameter-Modulated Nanowires. ACS Appl. Mater. Interfaces 2022, 14 (1), 1740– 1746,  DOI: 10.1021/acsami.1c20242
      There is no corresponding record for this reference.
    13. 13
      Blandre, E.; Chaput, L.; Merabia, S.; Lacroix, D.; Termentzidis, K. Modeling the reduction of thermal conductivity in core/shell and diameter-modulated silicon nanowires. Phys. Rev. B 2015, 91 (11), 115404  DOI: 10.1103/PhysRevB.91.115404
      There is no corresponding record for this reference.
    14. 14
      Ko, M.; Baek, S. H.; Song, B.; Kang, J. W.; Kim, S. A.; Cho, C. H. Periodically Diameter-Modulated Semiconductor Nanowires for Enhanced Optical Absorption. Adv. Mater. 2016, 28 (13), 2504– 2510,  DOI: 10.1002/adma.201505144
      There is no corresponding record for this reference.
    15. 15
      Oliveira, D. S.; Tizei, L. H. G.; Ugarte, D.; Cotta, M. A. Spontaneous Periodic Diameter Oscillations in InP Nanowires: The Role of Interface Instabilities. Nano Lett. 2013, 13 (1), 9– 13,  DOI: 10.1021/nl302891b
      There is no corresponding record for this reference.
    16. 16
      Sutter, P.; Sutter, E. Tunable 1D van der Waals Nanostructures by Vapor-Liquid-Solid Growth. Acc. Chem. Res. 2023, 56 (22), 3235– 3245,  DOI: 10.1021/acs.accounts.3c00502
      There is no corresponding record for this reference.
    17. 17
      Sutter, E.; Kisslinger, K.; Wu, L.; Zhu, Y.; Yang, S.; Camino, F.; Nam, C. Y.; Sutter, P. Single Crystalline GeSe Van Der Waals Ribbons With Uniform Layer Stacking, High Carrier Mobility, and Adjustable Edge Morphology. Small 2024, 20 (50), 2406129  DOI: 10.1002/smll.202406129
      There is no corresponding record for this reference.
    18. 18
      Liu, Y.; Jin, L.; Pandey, T.; Sun, H.; Liu, Y.; Li, X.; Rodriguez, A.; Wang, Y.; Zhou, T.; Chen, R. Anomalous thermal transport in Eshelby twisted van der Waals nanowires. Nat. Mater. 2025, 24 (5), 728– 734,  DOI: 10.1038/s41563-024-02108-3
      There is no corresponding record for this reference.
    19. 19
      Song, H.; Ji, S.; Kang, S. G.; Shin, N. Contact Geometry-Dependent Excitonic Emission in Mixed-Dimensional van der Waals Heterostructures. ACS Nano 2024, 18 (29), 19179– 19189,  DOI: 10.1021/acsnano.4c04770
      There is no corresponding record for this reference.
    20. 20
      Jiang, K.; You, Q.; Zheng, Y.; Fang, F.; Xie, Z.; Li, H.; Wan, Y.; Han, C.; Shi, Y. Oriented Epitaxial Growth of Mixed-Dimensional van der Waals Heterostructures with One-Dimensional (1D) Bi2S3 Nanowires and Two-Dimensional (2D) WS2 Monolayers for Performance-Enhanced Photodetectors. Nano Lett. 2024, 24 (45), 14437– 14444,  DOI: 10.1021/acs.nanolett.4c04455
      There is no corresponding record for this reference.
    21. 21
      Lv, Q.; Tan, J.; Wang, Z.; Gu, P.; Liu, H.; Yu, L.; Wei, Y.; Gan, L.; Liu, B.; Li, J.; Kang, F.; Cheng, H.-M.; Xiong, Q.; Lv, R. Ultrafast charge transfer in mixed-dimensional WO3-x nanowire/WSe2 heterostructures for attomolar-level molecular sensing. Nat. Commun. 2023, 14 (1), 2717,  DOI: 10.1038/s41467-023-38198-x
      There is no corresponding record for this reference.
    22. 22
      Yang, X.; Wu, R.; Zheng, B.; Luo, Z.; You, W.; Liu, H.; Li, L.; Zhang, Y.; Tan, Q.; Liang, D. A Waveguide-Integrated Two-Dimensional Light-Emitting Diode Based on p-Type WSe2/n-Type CdS Nanoribbon Heterojunction. ACS Nano 2022, 16 (3), 4371– 4378,  DOI: 10.1021/acsnano.1c10607
      There is no corresponding record for this reference.
    23. 23
      Sutter, E.; Sutter, P. 1D Wires of 2D Layered Materials: Germanium Sulfide Nanowires as Efficient Light Emitters. ACS Appl. Nano Mater. 2018, 1 (3), 1042– 1049,  DOI: 10.1021/acsanm.7b00053
      There is no corresponding record for this reference.
    24. 24
      Sutter, P.; Idrobo, J. C.; Sutter, E. Van der Waals Nanowires with Continuously Variable Interlayer Twist and Twist Homojunctions. Adv. Funct. Mater. 2021, 31 (9), 2006412  DOI: 10.1002/adfm.202006412
      There is no corresponding record for this reference.
    25. 25
      Sutter, E.; French, J. S.; Sutter, P. Tunable Layer Orientation and Morphology in Vapor–Liquid–Solid Growth of One-Dimensional GeS van der Waals Nanostructures. Chem. Mater. 2021, 33 (11), 3980– 3988,  DOI: 10.1021/acs.chemmater.1c00289
      There is no corresponding record for this reference.
    26. 26
      Dolado, J.; Renforth, K. L.; Nunn, J. E.; Hindsmarsh, S. A.; Hidalgo, P.; Sánchez, A. M.; Méndez, B. Zn2GeO4/SnO2 Nanowire Heterostructures Driven by Plateau–Rayleigh Instability. Cryst. Growth Des. 2020, 20 (1), 506– 513,  DOI: 10.1021/acs.cgd.9b01494
      There is no corresponding record for this reference.
    27. 27
      Mead-Hunter, R.; King, A. J.; Mullins, B. J. Plateau Rayleigh instability simulation. Langmuir 2012, 28 (17), 6731– 6735,  DOI: 10.1021/la300622h
      There is no corresponding record for this reference.
    28. 28
      Shabahang, S.; Kaufman, J. J.; Deng, D. S.; Abouraddy, A. F. Observation of the Plateau–Rayleigh capillary instability in multi-material optical fibers. Appl. Phys. Lett. 2011, 99 (16), 161909  DOI: 10.1063/1.3653247
      There is no corresponding record for this reference.
    29. 29
      Malone, B. D.; Kaxiras, E. Quasiparticle band structures and interface physics of SnS and GeS. Phys. Rev. B 2013, 87 (24), 245312  DOI: 10.1103/PhysRevB.87.245312
      There is no corresponding record for this reference.
    30. 30
      Li, C.; Yu, Y.; Chi, M.; Cao, L. Epitaxial Nanosheet-Nanowire Heterostructures. Nano Lett. 2013, 13 (3), 948– 953,  DOI: 10.1021/nl303876a
      There is no corresponding record for this reference.
    31. 31
      Ribeiro, H. B.; Ramos, S. L. L. M.; Seixas, L.; de Matos, C. J. S.; Pimenta, M. A. Edge phonons in layered orthorhombic GeS and GeSe monochalcogenides. Phys. Rev. B 2019, 100 (9), 094301  DOI: 10.1103/PhysRevB.100.094301
      There is no corresponding record for this reference.
    32. 32
      Hsueh, H. C.; Warren, M. C.; Vass, H.; Ackland, G. J.; Clark, S. J.; Crain, J. Vibrational properties of the layered semiconductor germanium sulfide under hydrostatic pressure: Theory and experiment. Phys. Rev. B 1996, 53 (22), 14806,  DOI: 10.1103/PhysRevB.53.14806
      There is no corresponding record for this reference.
    33. 33
      Jadczak, J.; Andrzejewski, J.; Debus, J.; Ho, C. H.; Bryja, L. Resonant Exciton Scattering Reveals Raman Forbidden Phonon Modes in Layered GeS. J. Phys. Chem. Lett. 2023, 14 (17), 3986– 3994,  DOI: 10.1021/acs.jpclett.3c00783
      There is no corresponding record for this reference.
    34. 34
      Dayeh, S. A.; Yu, E. T.; Wang, D. Surface Diffusion and Substrate-Nanowire Adatom Exchange in InAs Nanowire Growth. Nano Lett. 2009, 9 (5), 1967– 1972,  DOI: 10.1021/nl900191w
      There is no corresponding record for this reference.
    35. 35
      Dayeh, S. A.; Mack, N. H.; Huang, J. Y.; Picraux, S. T. Advanced core/multishell germanium/silicon nanowire heterostructures: The Au-diffusion bottleneck. Appl. Phys. Lett. 2011, 99 (2), 023102  DOI: 10.1063/1.3567932
      There is no corresponding record for this reference.
    36. 36
      Lee, Y.; Shin, N. Mechanistic insights into diffusion-controlled 2D WSe2 growth via chemical vapor deposition in confined spaces. FlatChem. 2025, 51, 100863  DOI: 10.1016/j.flatc.2025.100863
      There is no corresponding record for this reference.
    37. 37
      Suzuki, H.; Hashimoto, R.; Misawa, M.; Liu, Y.; Kishibuchi, M.; Ishimura, K.; Tsuruta, K.; Miyata, Y.; Hayashi, Y. Surface Diffusion-Limited Growth of Large and High-Quality Monolayer Transition Metal Dichalcogenides in Confined Space of Microreactor. ACS Nano 2022, 16 (7), 11360– 11373,  DOI: 10.1021/acsnano.2c05076
      There is no corresponding record for this reference.
    38. 38
      Li, S.; Hong, J.; Gao, B.; Lin, Y.-C.; Lim, H. E.; Lu, X.; Wu, J.; Liu, S.; Tateyama, Y.; Sakuma, Y.; Tsukagoshi, K.; Suenaga, K.; Taniguchi, T. Tunable Doping of Rhenium and Vanadium into Transition Metal Dichalcogenides for Two-Dimensional Electronics. Adv. Sci. 2021, 8 (11), 2004438  DOI: 10.1002/advs.202004438
      There is no corresponding record for this reference.
    39. 39
      Kim, J.; Jin, C.; Chen, B.; Cai, H.; Zhao, T.; Lee, P.; Kahn, S.; Watanabe, K.; Taniguchi, T.; Tongay, S.; Crommie, M. F.; Wang, F. Observation of ultralong valley lifetime in WSe2/MoS2 heterostructures. Sci. Adv. 2017, 3 (7), 1700518  DOI: 10.1126/sciadv.1700518
      There is no corresponding record for this reference.
    40. 40
      Musin, I. R.; Boyuk, D. S.; Filler, M. A. Surface chemistry controlled diameter-modulated semiconductor nanowire superstructures. J. Vac. Sci. Technol. B 2013, 31 (2), 020603  DOI: 10.1116/1.4792660
      There is no corresponding record for this reference.
    41. 41
      Christesen, J. D.; Pinion, C. W.; Hill, D. J.; Kim, S.; Cahoon, J. F. Chemically Engraving Semiconductor Nanowires: Using Three-Dimensional Nanoscale Morphology to Encode Functionality from the Bottom Up. J. Phys. Chem. Lett. 2016, 7 (4), 685– 692,  DOI: 10.1021/acs.jpclett.5b02444
      There is no corresponding record for this reference.
    42. 42
      Sharmila, B.; Dwivedi, P. MoS2/SiNWs heterostructure based repeatable and highly responsive photodetector. Opt. Mater. 2022, 133, 112918  DOI: 10.1016/j.optmat.2022.112918
      There is no corresponding record for this reference.
    43. 43
      Ananth, R.; Utama, M. I. B.; Xu, D. D.; Vong, A. F.; Sadhukhan, T.; Zeng, H.; López-Arteaga, R.; Wang, W.; Namgung, S. D.; Gavin, S. C. Enhanced spectral purity of WSe2 quantum emitters via conformal organic adlayers. Sci. Adv. 2025, 11 (40), eady7557  DOI: 10.1126/sciadv.ady7557
      There is no corresponding record for this reference.
    44. 44
      Wu, C.-H.; Reep, T.; Huang, Y.; Brems, S.; Haffner, C.; Huyghebaert, C.; Kuyken, B.; Van Campenhout, J.; Pantouvaki, M.; Van Thourhout, D. Low-loss phase modulation using a MoS2 monolayer integrated on silicon waveguides. 2D Mater. 2025, 12 (4), 045006  DOI: 10.1088/2053-1583/ade9d9
      There is no corresponding record for this reference.

  • Supporting Information

    Supporting Information

    The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.nanolett.5c04385.

    • SEM image of Au nanoparticles dispersed on Si substrate and optical microscopic images of as-grown and dry-transferred GeS nanowires. TEM and EDS analyses of straight and core–shell nanowires. EDS spectra of core–shell GeS nanowires. Raman spectrum of a periodic core–shell GeS nanowire. Additional SEM images of periodic core–shell GeS nanowires at different growth durations. Statistical distributions of shell diameters and shell contact angles as a function of growth time. Comparison of shell-thicknesses measurements by AFM and SEM. Shell and core diameter comparison between upper and lower segments. Comparison of core and shell diameters at the upper and lower segments in periodic nanowires. Schematic comparing periodic shell and conformal shell structures. PL measurements on a core–shell GeS nanowire. PL spectra comparison between shell contact and intershell regions. UPS analysis of GeS. Superimposed PL intensity maps at the GeS and WSe2 emission wavelengths. PL peak deconvolution near the GeS/WSe2 junction regions. Comparison of P-R instability in nanowires reported in previous studies. (PDF)


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