Broadband photodetectors with enhanced performance in UV–Vis–NIR band based on PbS quantum dots /ZnO film heterostructure

The formation of a broadband photodetector with high response, high sensitivity and controllable band is a major challenge to improve the application range of photodetectors. The integration of quantum dots and highly conductive materials is one of the important approach for the application of broadband photodetectors. In this work, ultraviolet–visible–near infrared (UV–Vis–NIR) sensitive PD consisting of ZnO film/PbS quantum dots (QDs) heterostructure was proposed. While forming a built-in electric field, the heterostructure also generates a barrier to prevent carrier recombination, so that the heterostructure PD has excellent photoresponse performance in the UV–Vis–NIR range, and the peak responsivity is increased by 550%. Increased from 0.974 mA/W to 6.332 mA/W, accompanied by obvious red shift, faster response and recovery speed compared to pure ZnO film PD. Different from other experiments, in order to make the performance gain of PbS QDs on ZnO film more obvious and intuitive, this article uses RF magnetron sputtering to prepare ultra-thin ZnO film, and discusses the impact of PbS QDs on the photoelectric properties of ZnO film more comprehensively and systematically. The performance of the broad spectrum in this experiment will be of great help to the research and application of ZnO PD in the future.