Improvement in Response Speed of a AgSbS<sub>2</sub> Photodetector by Alloy Engineering
Wenjing Zhai, Wenhao Zheng, Zhihang Zhang, Lin Huang, Bing Yu, Liufang Chen, Guangyuan Li, Xinyu Li, Xiaohui Zhou, Lin Lin, Z. B. Yan, Chao Chen, Xiangping Jiang, Jun‐Ming Liu
Abstract
The ternary metal chalcogenide AgSbS 2 has been regarded as a promising photovoltaic compound due to its excellent stability and nontoxicity. However, the response time of the as-prepared AgSbS 2 photodetectors is longer by several orders of magnitude than the time required for practical application, appealing to an improving strategy by alloy engineering. Herein, we fabricated AgSb 1– x Bi x S 2 ( x = 0–0.5) photodetectors and investigated their photoresponse behaviors. In comparison with the AgSbS 2 photodetector, the as-prepared AgSb 0.7 Bi 0.3 S 2 photodetector demonstrates a remarkable reduction in response time by more than 3 orders of magnitude. It is found that the trap level of AgSb 0.7 Bi 0.3 S 2 is ∼0.2 eV shallower than that of AgSbS 2, which contributes to the dramatic decrease in response time. This work demonstrates that alloy engineering provides an effective solution to considerably shorten photodetector response time and essentially facilitates device optimization.