Comparision of sol-gel and sputtering method properties of TiO2 thin film ultraviolet sensor

The objective of this paper is to realize a UV sensor with an Al/TiO₂/ITO structure and the high quality TiO₂ thin films were grown on ITO substrates prepared by sputtering and the sol-gel method at 300degC. The proposed UV device adopted metal semiconductor metal (MSM) light-dependent resistor has characteristics of varying film thickness, and high photo-electric and stability. The photo-electric measurements show that thin film thickness could remarkably influence the photo-electric properties of the TiO₂ electrodes. In the sputtering method, film is produced 300 nm with high quality crystal and strong photoelectric activity, showing the largest photo-current. With the sol-gel method, film is produced at 50 nm showing the largest photo-current. The UV photo response of sputtered TiO₂ film and sol-gel TiO₂ film were about 0.14 mAW^-1 and 0.06 mAW^-1 respectively. In this study, the crystal quality, optical and electrical properties of these high quality TiO₂ thin films were investigated using scanning electron microscopy (SEM), optical absorption and I-V measurements.