26‐3: Room Temperature Bias‐Selectable, Dual‐Band Ultraviolet/Infrared Detectors Based on PTAA/MAPbCl3 Single Crystal film Heterojunction

A single photodetector capable of switching its peak spectral photoresponse between two wavelength bands is highly useful, particularly for the ultraviolet‐infrared bands in applications such as remote sensing, object identification, and chemical sensing. However, it is difficult to realize dual‐frequency ultraviolet/infrared detection with the existing technology. In this study, we leverage the advantages of perovskites materials to demonstrate a bias‐selectable ultraviolet/infrared dual‐band detector that operates at room temperature by using CH 3 NH 3 PbCl 3 (MAPbCl 3 ) single ctystal film and poly(triaryl amine). By switching between zero and forward bias, this detectors switch peak photosensitive ranges between the ultraviolet and infrared bands with room temperature detectivities of 4.5 × 10 12 and 1.65 × 10 9 cm Hz 1/2 W −1 , respectively. Unlike conventional bias‐selectable detectors, which utilize a set of back‐to‐back photodiodes, we demonstrate that under zero/forward bias conditions the device's operation mode instead changes between photovoltaic effect and photoconductive effect / the radiant thermal effect, allowing additional functionalities that the conventional structure cannot provide.