Highly sensitive and stable room-temperature gas sensors based on the photochemically activated p-type CuAlO2 thin films

Abstract

Activating metal oxide-based gas sensors using UV-LED is a promising approach to operating them at low temperatures. This method preserves the film characteristics, thereby ensuring the stability of the devices. In this report, we present a remarkably sensitive and stable gas sensor based on solution-processed p-type copper aluminum oxide (CuAlO2), which can sense O3 gas at room temperature. Moreover, the sensitivity is further improved through exposure to ultraviolet (UV) radiation. The optimal gas response of 12.32 can be achieved under UV illumination of 20 mW/cm2 at room temperature. More importantly, the CuAlO2 sensor exhibits outstanding stability, with a deterioration of only ∼10% over a period of 3 months. These findings suggest that CuAlO2 is a promising material for gas sensing at room temperature.