High-Efficient Ultraviolet Photodetectors Based on TiO2/Ag/TiO2 Multilayer Films

In this paper, the TiO₂/Ag/TiO₂ (TAT) multilayer thin films were deposited on a corning glass substrate at room temperature using radio frequency magnetron sputtering technique. The TAT multilayer was characterized by field-emission scanning microscope, atomic force microscopy, X-ray diffraction, and ultraviolet (UV)-visible spectroscopy. The TAT multilayer can be optimized to obtain a transmittance more than 80%. With a 360-nm illumination and 5 V applied bias, it was found that the fabricated UV photodetectors (PDs) with TAT structure showed much higher photoresponse (10 A/W) than traditional TiO₂ metal-semiconductor-metal PDs (0.08 A/W). This indicated that the TAT multilayer structures have potential to be employed in the PD devices of high performance.