Enhanced Negative-Bias Illumination Temperature Stability of Praseodymium-Doped InGaO Thin-Film Transistors

The performance of praseodymium-doped indium gallium oxide (PrIGO) as the channel layer of thin-film transistors (TFTs) is widely investigated. The TFTs with Pr doping exhibit a remarkable suppression of the light-induced instability including a negligible photoresponse and significant enhancement in negative gate bias stress under illumination (NBITS). The structure, chemical composition, and oxygen vacancy concentration of PrIGO films are analyzed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. In addition, the low-frequency noise test is introduced to analyze the variation of trap density with Pr doping. The results indicate that the trap states induced by Pr doping facilitate the capture of free electrons by positively charged oxygen vacancies under illumination, which leads to the suppression of photoinduced carriers in the conduction band.