Enhancing the Performance of Broadband SbSe/GaO Self-Powered Photodetectors via Modulation of GaO Surface States and Their Application in All-Day Corona Detection.

The technology for photodetection and localization of corona discharge typically necessitates the integration of various photodetectors (PDs) with different photoresponse bands and relies on external power supplies. A self-powered PD was fabricated utilizing the SbSe/GaO heterojunction, exhibiting a broadband photoresponse from solar-blind ultraviolet (SBUV) to visible (Vis) and near-infrared (NIR) bands. The surface states of GaO nanorod array (NR) films were modulated by treatment with hydrogen peroxide (HO) solution for different periods of time to suppress the interface recombination of photogenerated carriers in type-I heterojunctions. The HO treatment resulted in increased hydroxyl groups (-OH) and decreased oxygen vacancies in GaO NRs. The -OH can facilitate oxygen molecule (O) adsorption in GaO NRs and form O to consume photogenerated holes to reduce the recombination of photogenerated carriers. However, the decrease of oxygen vacancies will cause a decline in the concentration of electrons in GaO NRs to hinder the carrier transport. Ultimately, the optimized Al/SbSe/GaO/FTO PD, subjected to HO treatment for 4 min, demonstrated responsivities of 3.3, 130, and 180 mA/W under 254, 525, and 850 nm light illumination without applying a bias voltage, respectively. The utilization of oxygen adsorption and desorption processes to regulate the recombination of photogenerated carriers at the interface is an effective strategy for improving the performance of I-type heterojunction self-powered PDs. An approach was conceptually proposed for all-day real-time corona discharge monitoring in high-voltage transmission lines by utilizing the broadband photoresponse characteristic of PDs. The SBUV photoresponse was applied for the capture of SBUV light signals generated by corona discharge. The photoresponse in Vis and NIR light bands was employed to provide background information on corona discharge in both strong light conditions during daytime and weak light conditions during nighttime. The results provide a low power and miniaturized solution for the digitalization of the Power Internet of Things (IoT) and enable real-time monitoring of high-voltage transmission lines.