Effect of surface modification by a self-assembled monolayer on the indium zinc oxide film-based ultraviolet photodetector

In this paper, indium zinc oxide (IZO) thin films were deposited on a quartz substrate by radio frequency magnetron sputtering. Surface analysis showed that the IZO film deposited under a flow ratio of 10% oxygen has the smoothest surface, and this was determined to the optimum parameter for the fabrication of the metal-semiconductor-metal (MSM) photodetector. In order to improve the response characteristics of the device, 3-aminopropyltrimethoxysilane (APTMS) was deposited onto the IZO film to improve its surface state, which could, in turn, reduce the negative effect of vacancies and suppress the leakage current path for the IZO photodetector. Following APTMS modification, the dark current of the IZO photodetector decreased by nearly an order and the rejection ratio increased from 325 to 728.