Thermo‐Phototronic‐Effect‐Enhanced Photodetectors Based on Porous ZnO Materials

Abstract Self‐powered ultraviolet (UV) photodetectors with metal–semiconductor–metal (MSM) structure have attracted extensive attention due to their simple configuration and the fact that they require no external power source. However, the stability of Schottky‐contact‐based ultraviolet photodetectors is still poor due to the difficulty of controlling the surface states in the semiconductor, where it is almost impossible to obtain the same Schottky barrier heights in different devices. An Ohmic‐contacted self‐powered ultraviolet photodetector with an MSM structure is constructed by utilizing porous ZnO, which can dramatically increase photodetection performance due to its thermo‐phototronic effect. The photocurrent signals of the photodetector at room temperature are 4.88 and 11.25 µA, which can be increased to 5.33 and 13.70 µA, respectively. The underlying physical mechanism of the performance enhancement is revealed through band‐diagram analysis. This work extends the types of ZnO material‐based photodetectors and holds great potential for developing high‐performance self‐powered ultraviolet photodetectors.