Importance of Structural Relaxation on the Electrical Characteristics and Bias Stability of Solution-Processed ZnSnO Thin-Film Transistors

Effect of structural relaxation (SR) on the electrical characteristics and bias stability of solution-processed zinc-tin oxide (ZTO) thin-film transistors (TFTs) were systematically investigated by controlling the annealing time of the ZTO semiconductor films. Note that SR was found to increase with increased annealing time. Due to the increased SR, the ratio of oxygen vacancies (V-O) increased from 21.5% to 38.2%. According to increased V-O, the mobility in the saturation region was exhibited by a sixfold increase from 0.38 to 2.41 cm(2) V-1 s(-1). In addition, we found that the threshold voltage negatively shifted from 3.08 to -0.95 V. Regarding the issue of bias stability, according to increased SR, positive-bias stress of the ZTO TFTs was enhanced, compared with reverse features of negative-bias stress. Our understanding is expected to provide a basic way to improve the electrical characteristics and bias stability of rare-metal-free oxide semiconductor TFTs, which have not been sufficiently studied.

Automated summary

By controlling the annealing time, the effect of structural relaxation on the electrical characteristics and bias stability of zinc-tin oxide thin-film transistors (TFTs) was investigated. Increased structural relaxation led to an increase in oxygen vacancies, resulting in higher mobility and a negative shift in threshold voltage. The positive-bias stress of the TFTs was enhanced with increased structural relaxation.