Investigation on Stability in Solution-Processed In-Zn-Sn-O TFT Array Under Various Intensity of Illumination

Abstract

The effect of light illumination intensity on the stability of In-Zn-Sn-O (IZTO) thin-film transistors (TFTs) array fabricated by solution processed is investigated. Comparison with positive bias stress, the light illumination suppresses the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{\text {th}}$ </tex-math></inline-formula> shift under positive bias illumination stress because of the increase in the free electrons induced by the ionized oxygen vacancies in the IZTO channel layer, but transfer characteristics show two-stage degradation under negative bias illumination stress (NBIS). The hump phenomenon is induced after NBIS, and the light illumination intensity is higher, the hump phenomenon becomes more serious. The hump phenomenon is relevant to ionized oxygen vacancies, which act as shallow donor-like states near the conduction-band minimum in IZTO.