p-CuGaO2/β-Ga2O3 interfaces: A high-throughput approach for interface prediction and generation for power device applications

This study integrates a p-type copper gallium oxide (p-CuGaO 2 ) interlayer to enhance the performance of β-Ga 2 O 3 -based power devices, addressing challenges in achieving reliable p-type doping. The p-CuGaO 2 interlayer is expected to improve breakdown voltage (BV) and reduce leakage current, increasing device efficiency and reliability under high-temperature conditions. The heterojunction (HJ) system of β-Ga 2 O 3 and p-CuGaO 2 is investigated using density functional theory (DFT) via the Vienna Ab initio Simulation Package (VASP) and experimental methods, focusing on the β-Ga 2 O 3 (001)/p-CuGaO 2 (006) interface. Binding energy, electron localization, charge density difference, and electrostatic potential drop are analyzed, identifying Configuration-1 as the optimal configuration due to its high binding energy and favorable structural properties. Annealing temperature impacts the microstructure, stoichiometry, optical, electrical, and transport properties of p-CuGaO 2 /β-Ga 2 O 3 HJs. Electrical measurements reveal reduced turn-on voltage (V on ), on-resistance (R on ), and leakage currents, with the highest BV of 1.62 kV achieved at 800 °C compared to Pt/β-Ga 2 O 3 Schottky barrier diode (SBD). The interface state density (N SS ) is evaluated using the high-low frequency approach. Silvaco TCAD simulations explore breakdown mechanisms, demonstrating the potential of p-CuGaO 2 for β-Ga 2 O 3 HJ power devices. These findings support the development and manufacture of robust β-Ga 2 O 3 HJ power devices. We developed β-Ga 2 O 3 /p-CuGaO 2 HJ models using VASP and DFT to explore electronic properties. The p-CuGaO 2 film transitions from an amorphous to a polycrystalline phase at 800°C-annealing temperature. The HJ features a staggered-gap (type-II) band alignment, achieving a breakdown voltage of 1.62 kV, indicating strong potential for high-temperature applications. Silvaco TCAD simulations highlight the potential of these HJs for high-temperature power devices, particularly in challenging environments. • The p-CuGaO 2 (006)/β-Ga 2 O 3 (001) interface models with four heterostructures were investigated using the first principles based on DFT studies. • The p-CuGaO 2 /β-Ga 2 O 3 HJ annealed at 800 °C exhibits superior electrical characteristics including as compared to the as-deposited, 400 °C-annealed, and 600 °C-annealed samples. • The p-CuGaO 2 /β-Ga 2 O 3 HJs demonstrated their potential for high-temperature operation by achieving the highest BV of 1.62 kV at 800 °C. • Silvaco TCAD simulations explore breakdown mechanisms, demonstrating the potential of p-CuGaO 2 /β-Ga 2 O 3 HJ power devices. • The annealing process at 800 °C resulted in p-CuGaO 2 /β-Ga 2 O 3 HJs with excellent electrical properties and high quality, demonstrating their considerable potential for high-temperature applications.