Photoresistance Characteristics of ZnO:TiO2 Nano-Heterostructure Synthesized by Sol – Gel Method

Document Type : Research Paper

Authors

1 Department of Physics, College of Science, University of Babylon, Babylon, IRAQ.

2 Department of Physics, College of Science, University of Babylon, Babylon, IRAQ

3 College of Science, Al-Karkh University of Science, Baghdad, IRAQ.

Abstract

By examining the photoconductivity response process, the photoresistance of thin films made of ZnO, TiO2, ZnO:TiO2 hybrid, and ZnO/TiO2 was investigated. The samples were created utilizing the spray pyrolysis deposition method and the sol-gel process. A glass slide as used to deposit all thin films. Calculations of the optical energy gap have been performed using Tauc equation and UV-visible absorption spectra. SEM and X-ray diffraction were used to investigate structural characteristics. The hexagonal wurtzite and anatase phases of ZnO and TiO2 respectively were revealed by the XRD patterns. The photoresistance properties have been investigated for sandwich structure devices and light source to record current in both ON and OFF state. ZnO:TiO2 layer has shown significant decrease in the photoresistance with the exposure of light indicating narrowing of the depletion layer upon generation of charge carriers. The time dependency patterns were recorded for all sample devices to investigate the response and recovery duration upon exposure to light.

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