Improved high-performance ultraviolet photodetectors through controlled growth of ZnO lateral nanowires

Abstract

In order to create ultraviolet photodetectors with a high sensitivity, high detection rate, and high responsivity, the lateral growth of ZnO nanowires arrays was controlled on a quartz substrate by using a hydrothermal method. The combined effects of the ZnO seed layer and the high quality of the crystalline nanowire arrays with different lengths greatly improved the performance of the photodetectors. The photocurrent in the photodetectors prepared with the lateral nanowires was 103 times higher than that of the photodetector prepared with a ZnO film due to the photoconductive gain of nanowires. As the nanowire length increased, the responsivity increased and then decreased due to the surface action of nanowires and the influence of interpolation space. The ZnO nanowire photodetector with the optimal length showed significant performance improvements including a higher responsivity, larger detectivity, lower NEP, and extremely enhanced EQE of 14.9 A/W, 2.3 × 1012 jones, 3.0 × 10−13 WHz−1/2 and 5.0 × 103%, respectively. The controlled growth of lateral nanowires for use in high-performance photodetectors provides a feasible way to realize high efficiency light detection in future optoelectronic applications.