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

Abstract

We report an enhancement of near-infrared (NIR) detectability from amorphous InGaZnO (alpha-IGZO) thin film transistor in conjunction with randomly distributed molybdenum disulfide (MoS2) flakes. The electrical characteristics of the alpha-IGZO grown by radio-frequency magnetron sputtering exhibit high effective mobility exceeding 15 cm(2) V-1 s(-1) and current on/off ratio up to 10(7). By taking advantages of the high quality alpha-IGZO and MoS2 light absorbing layer, photodetection spectra are able to extend from ultra-violet to NIR range. The alpha-IGZO channel detector capped by MoS2 show a photo-responsivity of approximately 14.9 mAW(-1) at 1100 nm wavelength, which is five times higher than of the alpha-IGZO device without MoS2 layer.