Self-Powered Perovskite/CdS Heterostructure Photodetectors

Abstract

Methylammonium lead halide perovskites have attracted enormous attention due to their remarkable physical properties and potential for numerous (opto)electronic applications. Here, high-performance photodetectors based on CH3NH3PbI3 (MAPbI3)/CdS heterostructures, are demonstrated. The resulting self-powered MAPbI3/CdS photodetectors show excellent operating characteristics including a maximum detectivity of 2.3×10 11 Jones, responsivity of 0.43 A/W (both measured at 730 nm) and temporal response time of <14 ms. The mechanisms of charge separation and transport at the interface of the MAPbI3/CdS junction were investigated via conductive and photoconductive atomic force microscopy (C-AFM and PC-AFM). Obtained results show that grain boundaries exhibit higher photocurrent than flat regions of the top perovskite layer, which indicates that excitons preferentially separate at the edges of the perovskite crystals i.e. at the grain boundaries. The study of the photoelectric mechanism at the nanoscale provides essential insights for the fabrication of high-performance perovskitebased photodetectors, where the device performance could potentially be fine tuned through grain boundary engineering. The demonstrated self-powered photodetector are promising for numerous applications in low-energy consumption optoelectronic devices.

Bromine Doping of MAPbI3 Films Deposited via Chemical Vapor Deposition Enables Efficient and Photo‐Stable Self‐Powered Photodetectors

“…The responsivity and detectivity of self‐powered photodetectors obtained in the present study were compared with reported perovskite‐based sandwiched‐type devices, as shown in Figure . [ 8,19,42,45–52 ] The responsivity and detectivity reported in the present study are superior compared with prior relevant studies. The superior performance obtained from self‐powered photodetectors via CVD deposited perovskite films might be attributed to the high intrinsic quality of the perovskite films (high quality compact films and with no pinholes).…”

Band Alignment Engineering in Two‐Dimensional Transition Metal Dichalcogenide‐Based Heterostructures for Photodetectors

“…[ 145 ] In addition, conductive and photoconductive AFM (C‐AFM and PC‐AFM) were also used to study the mechanisms of photocurrent generation and transport across the heterointerface. [ 149,150 ] Li et al used C‐AFM and PC‐AFM to measure the dark current and photocurrent of WS 2 /CH 3 NH 3 PbI 3 heterostructures. [ 149 ] Density functional theory (DFT) calculations indicate a type‐II band alignment of WS 2 /CH 3 NH 3 PbI 3 heterostructures.…”

Excellent Excitonic Photovoltaic Effect in 2D CsPbBr3/CdS Heterostructures

“…The excellent PV performances of the CsPbBr 3 /CdS are superior to the similar dimensional 2D p-n PV devices [30][31][32][33] and comparable to that of perovskite-based film solar cells. [34][35][36] The detailed performance parameters are shown in Table S1, Supporting Information.…”