The Influence of Electrolytes on the Performance of Self-Powered Photoelectrochemical Photodetector Based on α -Ga 2 O 3 Nanorods.

Photodetectors have a wide range of applications across various fields. Self-powered photodetectors that do not require external energy have garnered significant attention. The photoelectrochemical type of photodetector is a self-powered device that is both simple to fabricate and offers high performance. However, developing photoelectrochemical photodetectors with superior quality and performance remains a significant challenge. The electrolyte, which is a key component in these detectors, must maintain extensive contact with the semiconductor without degrading its material quality and efficiently catalyze the redox reactions of photogenerated electrons and holes, while also facilitating rapid charge carrier transport. In this study, α-Ga ₂ O ₃ nanorod arrays were synthesized via a cost-effective hydrothermal method to achieve a self-powered solar-blind photodetector. The impacts of different electrolytes-Na ₂ SO ₄ , NaOH, and Na ₂ CO ₃ -on the photodetector was investigated. Ultimately, a self-powered photodetector with Na ₂ SO ₄ as the electrolyte demonstrated a stable photoresponse, with the maximum responsivity of 0.2 mA/W at 262 nm with the light intensity of 3.0 mW/cm ² , and it exhibited rise and decay times of 0.16 s and 0.10 s, respectively. The α-Ga ₂ O ₃ nanorod arrays and Na ₂ SO ₄ electrolyte provided a rapid pathway for the transport of photogenerated carriers and the built-in electric field at the semiconductor-liquid heterojunction interface, which was largely responsible for the effective separation of photogenerated electron-hole pairs that provided the outstanding performance of our photodetector.