Cu2O/ZnO heterojunction self-powered photodetector performance regulation

Self-powered photodetectors, requiring no external bias, offer distinct advantages that render them ideal for a broad spectrum of applications. Efficient carrier separation and collection stand as foundational elements in the operation of these photodetectors. In this study, we delve into the refinement of Cu2O/ZnO heterojunction photodetectors. By varying the thickness of the ZnO layer, we controlled the separation and capture of carriers at the heterojunction, thus achieving adjustable photodetector performance. Our experimental findings reveal pronounced performance trends related to different wavelength bands, with particular significance in the ultraviolet and visible exploration. We observe a distinctive pattern marked by an initial performance increase followed by a subsequent decline. This intriguing phenomenon implies that meticulous control over carrier separation and collection within the heterojunction can be realized by fine-tuning the transmission distance, ultimately allowing us to adjust the photodetector's responsivity.