Abstract

 This work demonstrates TeOx/ β-Ga2O3 heterojunction diodes, in which the tellurium oxide (TeOx) stoichiometry and bandgap (1.44–3.32 eV) were tuned by controlling the oxygen partial pressure during Te sputtering. All TeOx films consistently formed a type-II band alignment with β-Ga2O3, enabling favorable carrier transport. The optimized device achieved a low turn-on voltage of 1.26 V and a P-FOM of 0.4 GW/cm2, comparable to that of heterojunction diodes using other p-type materials. It exhibits clear advantages in co-optimizing the performances of forward conduction and reverse blocking. The device also shows excellent thermal stability, maintaining reliable operation from 93 to 523 K. These results suggest that TeOx is a promising p-type oxide for next-generation β-Ga2O3-based power devices and wide-temperature-range applications.