In situ heteroepitaxial construction and transport properties of lattice-matched α-Ir2O3/α-Ga2O3 p-n heterojunction

The construction of Ga2O3-based p-n heterojunction offers an alternative strategy to realize bipolar power devices; however, lattice mismatch usually leads to undesirable device performance and makes interface engineering more challenging. In this work, we demonstrated the construction of lattice-matched p-n heterojunctions by the in situ hetero-epitaxy of p-type alpha-Ir2O3 on n-type Si-doped alpha-Ga2O3 using the mist-chemical vapor deposition technique. The alpha-Ga2O3/alpha-Ir2O3 p-n heterojunction shows single-crystalline corundum structures and well-defined rectifying characteristics. The transport mechanism has been identified to be space-charge-limited current conduction, which is induced by interfacial traps in an ultrathin disordered layer at the alpha-Ga2O3/alpha-Ir2O3 interface. Through thermal treatment in oxygen ambient, interfacial trapping states are suppressed, and more shallow acceptors of Ir vacancies are activated, both of which lead to the profound reduction of reverse leakage current, thus the improved current rectification ratio. The p-type alpha-Ir2O3 with advantages of lattice matching to alpha-Ga2O3 provides a promising strategy to realize high-performance bipolar power devices.

Automated summary

The construction of lattice-matched p-n heterojunctions using mist-chemical vapor deposition technique on n-type Si-doped alpha-Ga2O3 has demonstrated the potential to improve device performance and rectifying characteristics. Through thermal treatment in oxygen ambient, the reduction of reverse leakage current and the improvement of current rectification ratio were achieved by suppressing interfacial trapping states and activating more shallow acceptors of Ir vacancies in the thin disordered layer at the alpha-Ga2O3/alpha-Ir2O3 interface. The p-type alpha-Ir2O3 with lattice matching properties provides a promising strategy for high-performance bipolar power devices.