High-mobility p-type semiconducting two-dimensional β-TeO2

Bilayer beta tellurium dioxide nanosheets with p-type characteristics can be formed through the surface oxidation of a mixture of tellurium and selenium, and used to create transistors with performance that matches their n-type oxide counterparts. Wide-bandgap oxide semiconductors are essential for the development of high-speed and energy-efficient transparent electronics. However, while many high-mobility n-type oxide semiconductors are known, 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. Here, we report the growth of bilayer beta tellurium dioxide (beta-TeO2), which has recently been proposed theoretically as a high-mobility p-type semiconductor, through the surface oxidation of a eutectic mixture of tellurium and selenium. The isolated beta-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 10(6) and a field-effect hole mobility of up to 232 cm(2) V-1 s(-1) at room temperature. A low effective mass of 0.51 was observed for holes, and the carrier mobility reached 6,000 cm(2) V-1 s(-1) on cooling to -50 degrees C.

Automated summary

Bilayer beta tellurium dioxide nanosheets were successfully synthesized through surface oxidation of tellurium and selenium mixture, demonstrating high-mobility p-type semiconductor properties. These nanosheets have potential applications in transistor fabrication, showing p-type switching with a high on/off ratio and field-effect hole mobility of up to 232 cm(2) V-1 s(-1) at room temperature. The carrier mobility reached even higher values of 6,000 cm(2) V-1 s(-1) on cooling to -50 degrees C, indicating promising prospects for high-speed and energy-efficient transparent electronics.