Atomically Thin SnO-Based p-Channel Thin-Film Transistor and Low-Power Complementary Inverter

Atomically thin oxide semiconductors play a crucial role in the development of next-generation, cost-effective, and energy-efficient electronics. In this study, we successfully developed a high-performance, fully depleted-type <i>p</i>-channel oxide thin-film transistor (TFT) utilizing an atomically thin <i>p</i>-type tin monoxide (SnO) channel with a thickness of approximately 1 nm. The SnO channel was grown using a vacuum-free, solvent-free, metal-liquid printing process at a remarkably low temperature of 250°C in an ambient atmosphere.<br/>To enhance the performance of the <i>p</i>-channel SnO TFTs, we employed oxygen vacancy defect terminations for both the bulk-channel and back-channel of the SnO channel. As a result, the presented <i>p</i>-channel SnO TFTs exhibited favorable characteristics, including a reasonable TFT mobility of ~0.47 cm²V^-1s^-1, a high on/off current ratio of ~10⁶, a low-off current (&lt;10¹²A), and a subthreshold swing of ~2.5 V decade^-1, which was improved compared to the conventional<i> p</i>-channel SnO TFTs. Furthermore, we successfully developed a low-power oxide-TFT-based complementary metal-oxide-semiconductor (CMOS) inverter using the ultrathin <i>p</i>-SnO and <i>n</i>-In₂O₃ TFTs. The CMOS inverter demonstrated a high voltage gain of approximately 120 and achieved low-power operation, consuming less than 58 nW, for the <i>p</i>-SnO/<i>n</i>-In₂O₃-TFT-based CMOS inverter.<br/>This work highlights the significant potential of oxide-TFT-based CMOS logic development by leveraging atomically thin oxide material channels. It offers new opportunities for next-generation, energy-efficient, and cost-effective oxide TFT technology, with the added benefits of vacuum-free, solvent-free, and low-temperature processing techniques.