Lin-Bao Luo, Guo-An Wu, Yang Gao, Long-Zhen Qiu, Lin Liang, Chao Xie,* Zhi-Xiang Zhang, Xiao-Wei Tong, Feng-Xia Liang,*

Abstract:Hybrid organic-inorganic perovskite materials have recently attracted enormous attention due to their extraordinary physical properties and promising application in future optoelectronic devices and systems. In this study, we demonstrate a high-performance and broadband photodetector composed of Cs-doped FAPbI₃  perovskite/dinaphtho[2,3-b:2′,3′-f]thieno[3, 2-b]thiophene (DNTT) vertically stacked heterojunction, which showed high responsivity of 778 A/W, and specific detectivity of 1.04×10¹³ Jones. What is more, the photodetector displayed excellent stability and broadband responsivity to illumination ranging from deep ultraviolet (DUV) to near infrared (NIR) light. It was interesting to note that doping a little amount of [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) into perovskite film can result in a substantial increase in responsivity, specific detectivity and photoconductive gain. Specifically, the specific detectivity was as high as 7.96×10¹³ Jones, which is much higher than other devices with similar geometries. Such a device optimization can be ascribed to promoted electron-hole separation and electron accepting sites that can selectively trap electrons in the perovskite-PCBM bulk heterojunction (BHJ), according to experimental analysis.