Boosting the performance of crossed ZnO microwire UV photodetector by mechanical contact homo-interface barrier

One-dimensional(1D)micro/nanowires of wide band gap semiconductors have become one of the most promising blocks of high-performance photodetectors.However,in the axial direction of micro/nanowires,the carriers can transport freely driven by an external electric field,which usually produces large dark current and low detectivity.Here,an UV photodetector built from three cross-intersecting ZnO microwires with double homo-interfaces is demonstrated by the chemical vapor deposition and physical transfer techniques.Compared with the reference device without interface,the dark current of this ZnO double-interface photodetector is significantly reduced by nearly 5 orders of magnitude,while the responsivity decreases slightly,thereby greatly improving the normalized photocurrent-to-dark current ratio.In addition,ZnO double-interface photodetector exhibits a much faster response speed(~0.65 s)than the no-interface device(~95 s).The improved performance is attributed to the potential barriers at the microwire-microwire homo-interfaces,which can regulate the carrier transport.Our findings in this work provide a promising approach for the design and development of high-performance photodetectors.