Investigation of oxygen plasma treatment on the device performance of solution-processed a-IGZO thin film transistors

We reported the impact of oxygen plasma treatment on solution-processed amorphous indium gallium zinc oxide (a-IGZO) thin film transistors (TFTs). Plasma-treated devices showed higher mobility, larger on/off current ratio, but a monotonically increased SS with plasma treatment time as well. The phenomenon was mainly due to two components in oxygen plasma, atomic oxygen and O2+, according to the photoluminescence (PL) measurement. Atomic oxygen reacted with oxygen vacancies in channel layer resulting in an improved mobility, and O2+ tends to aggregated at the surface acting as trapping states simultaneously. Our study suggests that moderate oxygen plasma treatment can be adopted to improve the device performance, while O2+ should be eliminated to obtain good interfacial states.