摘要
In this study we measured the degrees to which the Schottky barrier heights (SBHs) are lowered in ZnO nanowire (NW) devices under illumination with UV light. We measured the I-V characteristics of ZnO nanowire devices to confirm that ZnO is an n-type semiconductor and that the on/off ratio is approximately 10 4. From temperature-dependent I-V measurements we obtained a SBH of 0.661 eV for a ZnO NW Schottky device in the dark. The photosensitivity of Schottky devices under UV illumination at a power density of 3 μW/cm 2 was 9186%. Variations in the SBH account for the superior characteristics of n-type Schottky devices under illumination with UV light. The SBH variations were due to the coupled mechanism of adsorption and desorption of O 2 and the increase in the carrier density. Furthermore, through temperature-dependent I-V measurements, we determined the SBHs in the dark and under illumination with UV light at power densities of 0.5, 1, 2, and 3μW/cm 2 to be 0.661, 0.216, 0.178, 0.125, and 0.068eV, respectively. These findings should be applicable in the design of highly sensitive nanoscale optoelectronic devices.