GaP–ZnS Pseudobinary Alloy Nanowires

Abstract

Multicomponent nanowires (NWs) are of great interest for integrated nanoscale optoelectronic devices owing to their widely tunable band gaps. In this study, we synthesize a series of (GaP)(1-x)(ZnS)(x) (0 ≤ x ≤ 1) pseudobinary alloy NWs using the vapor transport method. Compositional tuning results in the phase evolution from the zinc blende (ZB) (x < 0.4) to the wurtzite (WZ) phase (x > 0.7). A coexistence of ZB and WZ phases (x = 0.4-0.7) is also observed. In the intermediate phase coexistence range, a core-shell structure is produced with a composition of x = 0.4 and 0.7 for the core and shell, respectively. The band gap (2.4-3.7 eV) increases nonlinearly with increasing x, showing a significant bowing phenomenon. The phase evolution leads to enhanced photoluminescence emission. Strikingly, the photoluminescence spectrum shows a blue-shift (70 meV for x = 0.9) with increasing excitation power, and a wavelength-dependent decay time. Based on the photoluminescence data, we propose a type-II pseudobinary heterojunction band structure for the single-crystalline WZ phase ZnS-rich NWs. The slight incorporation of GaP into the ZnS induces a higher photocurrent and excellent photocurrent stability, which opens up a new strategy for enhancing the performance of photodetectors.

Enhanced Stability and Tunable Photoluminescence in Perovskite CsPbX3/ZnS Quantum Dot Heterostructure

“…We focus on all‐inorganic perovskite due to its simpler atomic structure with higher stability compared to CH 3 NH 3 PbX 3 . Previous synthesis of heterostructures mainly relied on three methods, i.e., atomic‐layer epitaxy, metal–organic vapor‐phase epitaxy, and molecular‐beam epitaxy, which often lead to hierarchical, coaxial core/shell, and segmented structures . Here, we employ a facile solution‐phase method that has been developed as an attractive approach for colloidal nanostructures, and find that the synthesized CsPbX 3 /ZnS QD heterodimer has high quality with enhanced stability.…”

Semiconductor Solid‐Solution Nanostructures: Synthesis, Property Tailoring, and Applications

“…Our group has reported the synthesis of (GaP) 1− x (ZnS) x with x < 0.07 and (GaP) 1− x (ZnSe) x with 0.182 < x < 0.209 solid‐solution nanowires (Figure d–g) using two‐channel CVD method . Later, Park et al broadened the solubility of (GaP) 1− x (ZnS) x nanowires to the entire composition range of 0 ≤ x ≤ 1 using vapor transport method and a continuous phase transition as a dependence of ZnS content has been observed. The (GaP) 1− x (ZnS) x nanowires first exist in the form of ZB ( x < 0.4), and then the coexistence of ZB and WZ phases ( x = 0.4–0.7), and finally the WZ phase ( x > 0.7).…”

“…Compared with binary and ternary solid‐solutions, quaternary semiconductor solid‐solution exhibits some unexpected properties valuable for technological applications in diverse fields. So far, the quaternary semiconductor solid‐solutions have been reported for groups (II–VI)–(II–VI), (III–V)–(III–V), and (II–VI)–(III–V) material systems, which mainly include ZnCdSSe, ZnCdSeTe, GaInAsSb, GaN‐ZnO, GaP‐ZnS, GaP‐ZnSe, and GaAs‐ZnSe …”

Design Principles and Material Engineering of ZnS for Optoelectronic Devices and Catalysis

“…Other than the materials summarized above, narrow bandgap semiconductors, including GaP, GaAs, and InP, have also been studied for compositing with ZnS due to their high light absorption, matching band structure, and high carrier mobility . ZnS nanowire arrays grown on GaAs substrate using Ga as catalyst were reported by Liang et al The device was ultrasensitive to UV light while almost blind to visible light, indicating its excellent spectral selectivity as a UV sensor.…”