Deep UV Ta₂ O₅/Zinc-Indium-Tin-Oxide Thin Film Photo-Transistor

The authors report the fabrication of a deep-ultraviolet sensitive a-ZITO thin-film-transistor (TFT) with a Ta2O5gate dielectric. It is found that carrier mobility, threshold voltage, and sub-threshold swing are 106.2 cm2/Vs, 0.75 V, and 0.45 V/decade, respectively, measured in the dark. It is also found that measured current increased from 2.3 × 10-9A to 7.97 × 10-5A, as we illuminated the sample with λ = 250-nm UV light when VGis biased at 0 V. Furthermore, it is found that deep-UV-to-visible rejection ratio could reach 2.3 × 105for the fabricated Ta2O5/a-ZITO TFT.