Paper based self-powered UV photodiode: Enhancing photo-response with AZO back-field layer

The development of self-powered UV photodiode on green substrate is still a challenge. In this study, highly conductive Al doped ZnO (AZO) film was sputter-deposited on paper substrate at room temperature; subse-quently, paper-based Schottky photodiodes were successfully fabricated by following Au-ZnO-Al and Au-ZnO-AZO-Al structure designs, respectively. These UV light-based devices operate successfully without external power. Au-ZnO-AZO-Al photodiode shows improved response and faster speed compared to Au-ZnO-Al photo -diode. The one-dimensional Poisson simulation results demonstrate that the improvement is attributed to the strong electric field in the ZnO-AZO n-n+ high-low junction, thus, enhancing the collection rate and drifting speed of the photogenerated carriers. In addition, AZO can form favorable ohmic contact with the Al electrodes, further improving the device performance. The photo-response of the paper-based photodiode device shows high reproducibility and stability. Based on these outstanding results, we conclude that these paper-based electronic devices have great potential to replace conventional petroleum-based flexible electronic devices, thus, contrib-uting to the green/sustainable development.

Automated summary

In this study, a self-powered UV photodiode on a green substrate was successfully developed using a highly conductive AZO film and different electrode designs. The paper-based Schottky photodiodes operated without external power, with the Au-ZnO-AZO-Al structure showing improved response and faster speed compared to the Au-ZnO-Al structure. The enhancement in performance was attributed to the strong electric field in the ZnO-AZO n-n+ junction and the favorable ohmic contact between AZO and Al electrodes.