Enhanced Performance of In2O3/SnO2 Dual-Channel Thin-Film Transistor by Heterostructure Strategy

Metal-oxide thin-film transistors (TFTs) are promising for next-generation display backplanes and large-area electronics, while single-channel oxide TFTs often suffer from trade-offs among mobility, leakage current, and switching behavior. Here, an In2O3/SnO2 dual-channel TFT was fabricated by magnetron sputtering to combine the high electron transport capability of In2O3 with the leakage-suppression characteristics of SnO2. Compared with single-layer In2O3, single-layer SnO2, and reverse-stacked SnO2/In2O3 devices, the optimized In2O3/SnO2 TFT exhibits improved overall performance, with a linear mobility of 19.15 cm2/Vs, a subthreshold swing of 0.86 V/dec, an on/off current ratio of 3.58 × 106 and an optimized threshold voltage. The mobility is approximately 2.2 times higher than that of the single-layer In2O3 TFT, accompanied by obviously enhanced positive and negative stress stabilities. Furthermore, structural, chemical and optical analyses indicate that the enhanced performance can be attributed to the smooth heterointerface, favorable band alignment, and interfacial carrier redistribution between In2O3 and SnO2. The superior performance highlights the potential of the In2O3/SnO2 bilayer architecture for high-performance display-backplane switching and other large-area oxide-electronics applications.