Ultrahigh quantum efficiency of CuO nanoparticle decorated In2Ge2O7 nanobelt deep-ultraviolet photodetectors

Abstract

Although there has been significant progress in the fabrication and performance optimization of 1-D nanostructure-based deep-ultraviolet photodetectors, it is still a challenge to develop an effective device with high performance characteristics, such as high photocurrent–dark current ratio and high quantum efficiency. Herein, an efficient and simple method to fabricate high performance CuO nanoparticle decorated In₂Ge₂O₇ nanobelt deep-ultraviolet photodetectors is presented. A CuO coated In₂Ge₂O₇ nanobelt based photodetector showed very high responsivity (7.34 × 10⁵ A W⁻¹) and high quantum efficiency (3.5 × 10⁶). The underlying mechanism is proposed to be the formation of p–n heterojunctions between decorated nanoparticles and nanobelts, which enhances the spatial separation of photogenerated electrons and holes. This study opens up a new horizon for creation of novel photodetectors with high quantum efficiency.