$\hbox {Zr}_{0.27}\hbox {Ti}_{0.73}\hbox {O}_{2}$ -Based MSM Ultraviolet Detectors With Pt Electrodes

In this letter, visible-blind ultraviolet (UV) photodetectors based on Zr_0.27Ti_0.73O₂ thin films with Pt electrodes were fabricated. The Zr_0.27Ti_0.73O₂ thin films were prepared via the sol-gel method and characterized by means of X-ray diffraction, scanning electron microscopy, XPS, and UV-visible absorption spectra. At 5-V bias, the dark current of the detector was only 6 nA. Under the irradiation of 300-nm UV light, a high responsivity of 702.5 A/W was achieved due to the high internal gain. The high gain is caused by the introduction of zirconia. The rise and fall times of the device were 896.6 and 578.1 ms, respectively. Compared with TiO₂-based detectors, the Zr_0.27Ti_0.73O₂-based detector with Pt electrodes exhibits a much higher responsivity, a faster recovery time, and a wider detection range.