A new multispectral InGaZnO (IGZO) thin-film phototransistor (TF PT) based on a graded band-gap (GBG) SiGe capping layer with metallic nanoparticles (MNPs) is proposed. An accurate drain-current model is developed to investigate the device performances, where the optical characteristics under different light excitations (530 nm, 820 nm, and 1550 nm) are analyzed using the 3-D Finite-difference time-domain method (FDTD). |