Photoresponse of InGaZnO thin film transistor to ultraviolet illumination

An amorphous indium gallium zinc oxide (IGZO) thin film transistor (TFT) was fabricated and its respose to 405 nm ultraviolet illumination was investigated. It is found that the OFF-state current is dramaticaly influenced by the illumation. The photoresponse, including photocurrent, rise time and recovery time, is dependent on the bias condition, especially the gate voltage (Vgs). Higher photocurrent and smaller rise time are observed at higher Vgs, indicating that a lower Vgs is desired for a faster recovery characteristic.