Enhancement of near-infrared detectability from InGaZnO thin film transistor with MoS₂ light absorbing layer

We report an enhancement of near-infrared (NIR) detectability from amorphous InGaZnO (α-IGZO) thin film transistor in conjunction with randomly distributed molybdenum disulfide (MoS₂) flakes. The electrical characteristics of the α-IGZO grown by radio-frequency magnetron sputtering exhibit high effective mobility exceeding 15 cm² V^-1 s^-1 and current on/off ratio up to 10⁷. By taking advantages of the high quality α-IGZO and MoS₂ light absorbing layer, photodetection spectra are able to extend from ultra-violet to NIR range. The α-IGZO channel detector capped by MoS₂ show a photo-responsivity of approximately 14.9 mA W^-1 at 1100 nm wavelength, which is five times higher than of the α-IGZO device without MoS₂ layer.