A Comparative Study of Metal–Semiconductor–Metal Ultraviolet Photodetectors Based on Ultrasonic Spray Pyrolysis Deposited Anatase and Rutile TiO2

Anatase and rutile TiO
₂
-based metal-semiconductor-metal (MSM) ultraviolet photodetectors (PDs) are fabricated and investigated. The TiO
₂
thin films are grown by the ultrasonic spray pyrolysis deposition and the TiO
₂
films are annealed at 400°C and 800°C to form the anatase and the rutile phases. The material characteristics were measured by X-ray diffraction, Raman spectrum, X-ray photoelectron spectroscopy, and photoluminescence. The optical characteristics such as refractive index, extinction coefficient, absorption coefficient, and optical reflectance were characterized. The electrical and optoelectronic characteristics of the anatase and rutile TiO
₂
MSM PDs were characterized, including current-voltage, Schottky barrier height, spectral responsivity, response time, and detectivity.