Interface engineering on ZnO/Au based Schottky junction for enhanced photoresponse of UV detector with TiO2 inserting layer

Abstract

Metal-oxide semiconductor ZnO shows enormous potential in the field of photoelectric detection. However, the adsorption of H2O/O2 on its surface unavoidably results in degradation in the photoresponse. Herein, Au–TiO2–ZnO (ATZ) ultraviolet (UV) photodetectors were designed to benefit the photosensing performance by weaken the surface state effect through tuning the Schottky junction interface with TiO2 insertion layer. As expect, 97% enhancement of IPh response together with three orders of magnitude decrease of dark current was triggered. This enhancement is owing to the efficiently separation and extraction of photoexcites under the effect of the stronger and expanding built-in field, which is a result of reduction of space charge density in barrier region induced by inhibiting H2O/O2 adsorption at the ZnO/Au interface. These findings here provide a promising method to boost performances of optoelectronic devices by interface engineering and could be extended to other semiconductor devices.