EurekAlert  April 5, 2021 Wide-bandgap p-type oxides have carrier mobilities that are one to two orders of magnitude lower due to strong carrier localization near their valence band edge. Researchers in Australia have grown bilayer beta tellurium dioxide (β-TeO2) through the surface oxidation of a eutectic mixture of tellurium and selenium. It is theoretically proposed as a high-mobility p-type semiconductor. The isolated β-TeO2 nanosheets are transparent and have a direct bandgap of 3.7 eV. Field-effect transistors based on the nanosheets exhibit p-type switching with an on/off ratio exceeding 106 and a field-effect hole mobility of up to 232 cm2 V−1 s−1 at room temperature. […]