GaP鈥揨nS Pseudobinary Alloy Nanowires
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- 作者：Kidong Park ; Jung Ah Lee ; Hyung Soon Im ; Chan Su Jung ; Han Sung Kim ; Jeunghee Park ; Chang-Lyoul Lee
- 刊名：Nano Letters
- 出版年：2014
- 出版时间：October 8, 2014
- 年：2014
- 卷：14
- 期：10
- 页码：5912-5919
- 全文大小：471K
- ISSN：1530-6992
文摘
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鈥?i>x(ZnS)x (0 鈮?x 鈮?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鈥?.7) is also observed. In the intermediate phase coexistence range, a core鈥搒hell structure is produced with a composition of x = 0.4 and 0.7 for the core and shell, respectively. The band gap (2.4鈥?.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.