Investigations on the Light-Induced Degradation of P-Channel Poly-Silicon Thin Film Transistors

The long-term effect of light on P-channel low-temperature polycrystalline silicon (LTPS) thin film transistors (TFTs) is investigated. Under red light illumination, the transfer characteristic curves shift to the positive direction. The observed stretched-exponential time dependence of threshold voltage shift (ΔV
TH
) can be attributed to the charge trapping effect rather than the effect of photo-generated carriers or defects. Dehydrogenation is help to eliminate the ΔV
TH
of P-channel TFTs. An improved method to effectively suppress light-induced degradation is proposed and verified experimentally.