Solar-blind ultraviolet photodetector derived from direct carrier transition beyond the bandgap of CdPS_(3) single crystals  

作　　者：Xinyun Zhou Shuo Liu Jiacheng Yang Junda Yang Fen Zhang Le Yuan Ruiying Ma Jiaqi Shi Qinglin Xia Mianzeng Zhong 

机构地区：[1]Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, Changsha, 410083, China

出　　处：《Nano Research》2024年第11期10042-10048,共7页纳米研究（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.12174451 and 12274467);the Science and Technology Innovation Program of Hunan Province(No.2022RC1199);the Natural Science Foundation of Hunan Province of China(No.2021JJ40795);the High Performance Computing Center of Central South University,Central South University Graduate Student Independent Exploration and Innovation Project(No.2024ZZTS0454 and 2024ZZTS0778).

摘　　要：Wide-bandgap semiconductors have demonstrated considerable potential for fabricating solar-blind ultraviolet (SBUV) photodetectors, which are extensively used in both civilian and military applications. Despite this promise, the limited variety of semiconductors with suitable bandgaps hampers the advancement of high-performance SBUV detectors. In this study, we synthesized CdPS_(3) transparent single crystals using the chemical vapor transport (CVT) method. Density functional theory (DFT) calculations suggest that the bandgap of CdPS_(3) decreases as the material’s thickness increases, a finding corroborated by subsequent absorption spectra and photoelectric response measurements. The as-prepared CdPS_(3) nanosheets were employed as channels in photodetectors, demonstrating outstanding photoelectric performance in the solar-blind ultraviolet range (at 254 and 275 nm) with high responsivity (0.3 A/W), high specific detectivity (5.5 × 10^(9) Jones), rapid response speed (2.6 ms/3.4 ms), and exceptionally low dark current (2 pA). It is noteworthy that these nanosheets exhibit almost no sensitivity to 365 nm and visible light irradiation, attributable to the direct carrier transition beyond the broad bandgap in CdPS_(3). Furthermore, high-quality imaging was achieved under different gate voltages using 275 nm ultraviolet light, underscoring the potential of CdPS_(3) as a new material for high-performance SBUV optoelectronic detection.

关 键 词：solar-blind ultraviolet PHOTODETECTORS CdPS_(3) high-quality imaging 

分 类 号：TN23[电子电信—物理电子学]