Energy-band engineering by 2D MXene doping for high-performance homojunction transistors and logic circuits

The homojunction based on Ti(3)C(2)Tx MXene-doped In2O3 and indium oxide as the channel layer is real-ized in high-performance metal oxide thin film transistors (TFTs). Doping of MXene into In2O3 results in n-type semiconductor behavior, realizing tunable work function of In2O3 from 5.11 to 4.79 eV as MXene content increases from 0 to 2 wt.%. MXene-doped In2O3-based homojunction TFT presents optimal per-formance with electron mobilities of greater than 27.10 cm(2)/(V s) at 240 degrees C, far exceeding the maximum mobility of 3.91 cm(2)/(V s) for single-layer In2O3 TFTs. The improved performance originates from boosting of a two-dimensional electron gas (2DEG) formed at carefully engineered In2O3/MXene-doped In2O3 ox-ide homojunction interface. Besides, the transformation in conduction mechanism leads to better stability of MXene-doped In2O3 homojunction devices compared to undoped bilayer In2O3. Low-frequency noise further illustrates that doping MXene into In2O3 helps to reduce the device trap density, demonstrating excellent electrical performance. A resistor-loaded unipolar inverter based on In2O3/0.5% MXene-In2O3 TFT has demonstrated full swing characteristics and a high gain of 13. The effective doping of MXene into constructed homojunction TFTs not only contributes to improved stability, but also provides an ef-fective strategy for designing novel homojunction TFTs for low-cost oxide-based electronics.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.