Filterless ultra-narrow-band perovskite photodetectors with high external quantum efficiency based on the charge collection narrowing mechanism enabled by electron blocking/hole transport layer

Abstract

Abstract Narrow-band perovskite photodetectors based on the charge collection narrowing (CCN) mechanism have developed rapidly owing to their narrow-band spectral response in the visible and near-infrared range. However, they face problems such as low external quantum efficiency (EQE) and an insufficiently narrow bandwidth. To solve these problems, a new method that uses the barrier effect between the electron blocking/hole transport layer and the perovskite absorption layer is proposed to realize the CCN mechanism. Based on this new method, a new narrow-band perovskite photodetector is designed. In the device, the electron blocking/hole transport layer plays the dual role of blocking the transport of photogenerated electrons in perovskite absorber layer-1 to the cathode and promoting the transport of photogenerated holes in perovskite absorber layer-2 to the anode. By changing the thickness of the perovskite absorber layer, an ultra-narrow-band perovskite photodetector with a full width at half maximum of 9 nm was finally realized. The simulation results showed that the peak EQE of the device with the optimal performance under zero bias was as high as 59.13%, and the spectral responsivity reached as high as 0.376 A W−1. Both of these metrics were higher than those of other existing narrow-band perovskite photodetectors based on the CCN mechanism.