ZnO Branched Nanowires and the p-CuO/n-ZnO Heterojunction Nanostructured Photodetector

The authors report the growth of ZnO branched nanowires on the CuO nanowires and the fabrication of p-CuO/n-ZnO heterojunction nanostructured photodetector (PD). It was found that the hydrothermally grown ZnO branched nanowires were reasonably uniform with an average length of 200 nm and an average diameter of 50 nm. Under forward bias, it was found that turn on voltage of the fabricated PD reduced from similar to 0.7 to similar to 0.2 V under ultraviolet (UV) illumination. It was also found that UV-to-visible rejection ratio of the fabricated device was larger than 100.