Effect of TiO2 Nanoparticle Modification on Ultraviolet Photodetection Properties of Al-Doped ZnO Nanowire Network

Abstract

This study was conducted in order to observe the changes in the ultraviolet (UV) photodetection characteristic when TiO2 nanoparticles are modified on the surface of an aluminum-doped zinc oxide (AZO) nanowire in an AZO nanowire network with enhanced conductivity. According to the experiment results, the UV photosensitivity under a bias of 5V was 52-fold in a bare AZO network, and it increased to 147-fold in the case when TiO2 nanoparticles were modified. The UV reset time decreased from 9 to 5s. The AZO nanowire onto which TiO2 nanoparticles were adsorbed showed an approximately 2-fold faster response time and an approximately 3-fold higher UV photosensitivity than the existing bare AZO nanowire. The faster UV photoresponse time of the AZO nanowire network with adsorbed TiO2 nanoparticles is because the adsorbed TiO2 nanoparticles serve as recombination sites for electrons excited by UV illumination. In addition, with enhanced UV photosensitivity, adsorbed TiO2 nanoparticles serve as electron donation sites that provide additional electrons to the AZO nanowire when UV light is turned on. © 2011 The Japan Society of Applied Physics.