【Device Papers】Interfacial modification of CuO/Ga₂O₃ by plasmonic Pt for high performance self-powered solar-blind UV photodetector

      Researchers from the Zhejiang University have published a dissertation titled "Interfacial modification of CuO/Ga₂O₃ by plasmonic Pt for high performance self-powered solar-blind UV photodetector" in Surfaces and Interfaces.

Abstract

      Applications for solar-blind photodetectors (PDs) vary widely and include space communications, ozone monitoring, and more. In this study, pulsed laser deposition (PLD) and ion sputtering were employed to develop an unusual self-powered deep ultraviolet (UV) photodetector based on CuO/Ga₂O₃ with a Pt nanoparticles (NPs) interface. The Pt NPs interface transforms the device design from heterojunction to Schottky junction. The device features a low dark current of 83.2 fA and performs a high photo-to-dark current (I_photo/I_dark) ratio of 1.72 × 10⁴, a specific detectivity (D*) of 9.98 × 10¹¹ Jones, and a quick decay time of 56 ms upon 254 nm UV light at 196.5 μW/cm² without any power supply. The CuO/Pt/Ga₂O₃ Schottky junction-based device outperforms the CuO/Ga₂O₃ heterojunction-based device in terms of detection capabilities in both biased and non-biased settings. This is explained by the Schottky barrier creation mechanism with both Ga₂O₃ and CuO films, as well as how the plasmon resonance effect (PR effect) balances the barrier on the Ga₂O₃ side. Furthermore, Pt NPs serve as a potential well, offering an additional recombination channel that accelerates the decay process when the light is turned off. Our findings pave the way for more optoelectronic uses of Ga₂O₃-based solar-blind UV photodetectors in the future.

A high-performance solar-blind photodetector based on a CuO/Pt/Ga₂O₃ Schottky junction is developed by introducing Pt nanoparticles as an interfacial modulator within the CuO/Ga₂O₃ heterojunction. The Schottky junction and the plasmon resonance effect caused by Pt nanoparticles are used to minimize the device's dark current and enhance its photocurrent, respectively. Furthermore, the Pt NPs serve as a potential well, providing an additional recombination channel that accelerates the decay process when the light is turned off. The present research highlights the application of metallic interfaces for regulating energy bands and improving the response performance of Ga₂O₃-based heterojunction self-powered devices.

DOI：

https://doi.org/10.1016/j.surfin.2024.105181