Defect modification in ZnInSnO transistor with solution-processed Al2O3 dielectric by annealing

The properties of solution-processed Al2O3 thin films annealed at different temperatures were thoroughly studied through thermogravimetry–differential thermal analysis, UV–vis-NIR spectrophotometer measurements, scanning electron microscopy, X-ray diffraction, atomic force microscopy and a series of electrical measurements. The solution-processed ZnInSnO thin films transistors (TFTs) with the prepared Al2O3 dielectric were annealed at different temperatures. The TFTs annealed at 600 °C have displayed excellent electrical performance such as the field-effect mobility of 116.9 cm2 V−1 s−1 and a subthreshold slope of 93.3 mV/dec. The performance of TFT device could be controlled by adjusting the annealing temperature. The results of two-dimensional device simulations demonstrate that the improvement of device performance are closely related with the reduction of interface defects between channel and dielectric and subgap density of stats (DOS) in the channel layer.