High‐mobility p‐type Te 0.65 Se 0.35 thin‐film transistors with self‐passivating contacts

Tellurium (Te) has emerged as a significant semiconductor material due to its intriguing physicochemical properties and great potential in next‐generation electronics and optoelectronics. The Se alloying method has been proved to be effective in improving the static control ability of Te semiconductor film. However, the traditional metal/semiconductor contact severely limits the mobility and on‐state current density of Te 0.65 Se 0.35 films due to the existence of interfacial Schottky barrier and insufficient charge injection efficiency. Here, we propose a TeO x self‐passivating assisted metal/semiconductor contact method to reduce the contact resistance, enabling ultrahigh mobility and on‐state current in the p‐type Te 0.65 Se 0.35 thin film transistors. The TeO x passivation layer with a higher work function reduces contact resistance and weakens the Schottky barrier by passivating possible defects on the Te 0.65 Se 0.35 surface and inhibiting elements diffusion in the materials. The TeO x self‐passivating assisted Te 0.65 Se 0.35 thin film field effect transistor has a contact resistance as low as 1.2 kΩ μm and a contact interface with a near‐zero Schottky barrier. Compared with the original device, the on‐state current is increased by about 5 times to 250 μA, the hole mobility is increased by about 4 times which is up to 88.8 cm 2 V −1 s −1 , and the on–off ratio is about 2 × 10 4 . The comprehensive performance has reached the leading level and achieved the highest hole mobility among the evaporated p‐type films. This method fills the gap in the large‐scale preparation and optimization of p‐type semiconductors, providing the possibility for industrial wafer‐level preparation.