α-TeO2 Oxide as Transparent p-Type Semiconductor for Low Temperature Processed Thin Film Transistor Devices

Abstract

In comparison to reports on n-type semiconducting oxides, p-type oxide semiconducting materials are still rare. Scarcely reported p-type oxide transistors demonstrated unsatisfactory environmental stability which still hinders their implementation for all oxide transistors and circuit applications. In this study, for the first time on α-TeO2 as an active channel material with p-type characteristics accessible by direct evaporation technique. Notably, the fabricated 5 nm α-TeO2 thin film in connection with an equally thin passivation layer exhibits a remarkable low processing temperature of 50 °C generating a hole mobility of 3.8 cm2 V−1 s−1, an on-state current of 966 µA, and an on/off ratio of 3.8 × 103. Additionally, the reproducibility of these devices confirmed a narrow variation in the TFT metrics, yielding an average hole mobility, on-current, and on/off ratio of 3.59 cm2 V−1 s−1, 914 µA, and 3.3 × 103, respectively. Furthermore, the devices are subjected to extensive stability testing under ambient atmospheric conditions that exhibits a marginal mobility reduction while maintaining a stable on/off ratio over 125-day period, highlighting their robust environmental stability. Notably, the low processing temperatures with both exceptional transistor performance and environmental endurance makes them suitable for the integration onto flexible substrates, particularly bendable/stretchable displays.