Improved stability of solution-processed ZnO thin film transistor pot-treated by ultraviolet annealng step

Abstract

We present electrical and structural features of solution-processed ZnO thin-film transistors (TFTs) grown via a chemical solution process post-treated by ultra violet (UV) annealing step at processing temperature below 250°C. The transfer curves for the UV annealed ZnO TFTs, including around two-order higher on-current magnitude reveals only a negative drift of ?0.66 V in time for 15 days, compared with a ?9.29 V negative drift of the conventionally thermally annealed ZnO TFTs at 300°C. The observation of X-ray photoelectron spectroscopy clearly demonstrates the significant reduction of non-lattice oxygen vacancies via proper UV annealing step. The nature of improved stability in the UV-annealed ZnO TFTs is also described.