A dual-channel detection mode ZnO/organic polymer/Cu2O heterojunction dual-band photodetector

Abstract

Most photodetectors (PDs) can only perform optical detection in a fixed response range, and often cannot selectively control the response range, which greatly limits the development of emerging fields such as artificial intelligence, biosensing, optical communication and more. It is still a challenge to integrate dual-band detection and spectral identification into a single device for dual-channel optical detection. In this study, a dual-band PD that was synthesized by deposition of ZnO, organic polymer poly-(N-vinylcarbazole) (PVK) and Cu₂O semiconductor materials achieved a breakthrough. It is worth noting that the ZnO/PVK/Cu₂O PD can selectively convert the response band between 285–492 nm and 492–645 nm under bias voltage control. The peak responsivity of the PD is 0.19 A W⁻¹ at 450 nm under zero-bias conditions, while the peak responsivity is shifted to 556 nm with a peak of 0.20 A W⁻¹ at a voltage of −2.5 V under reverse connection. The dual-channel detection of blue and green light can be achieved with simple signal processing, which is closely matched with the emission spectrum of commercially available red, green and blue (RGB) white light emitting diodes (LEDs). This work provides design inspiration for potential applications of dual-band photodetectors in visible light communication, smart sensing devices and other emerging fields in the future.