Highly sensitive and fast perovskite photodetector functionalized by plasmonic Au nanoparticles-alkanethiol assembly

Abstract

We present a perovskite photodetector functionalized with Au NPs assembled with 3-mercaptopropionic acid (MPA), a short-chain alkanethiol (HS(CH2)nCOOH, n = 2), where the assembled Au NPs are embedded in the PEDOT:PSS layer of the hole transport layer. The incorporation of the Au NPs-MPA assembly not only enhances the responsivity strongly, but also improves the detectivity due to a reduction in dark current and enhances the response speed of the device. In particular, the responsivity, noise equivalent power (NEP), and response speed of the Au NPs-MPA assembly device significantly improved by approximately 4.1, 15.6, and 2.8 folds, respectively, as compared with those of the pristine device under visible light illumination. Our device exhibits a responsivity of ~2063 A W？1 and a NEP of ~1.93 × 10-14 W Hz？1/2 due to the incorporation of the Au NPs-MPA assembly, and a response time of ~300 ns is achieved by the fabrication of a short channel in the device. The improved charge extraction/transport and optical absorption by the introduction of Au NPs-MPA assembly lead to the overall improved device performance.