Epitaxial Growth of p-type β-Ga₂O₃ via Te and Mg Co-Doping Using Metal Organic Chemical Vapor Deposition

β-Gallium oxide (β-Ga₂O₃) offers considerable potential for next-generation power electronics due to its ultrawide bandgap (~4.9 eV) and established n-type conductivity. Nevertheless, realizing stable p-type doping remains a significant challenge, primarily due to the deep acceptor levels associated with conventional dopants. This article presents a co-doping strategy involving tellurium (Te) and magnesium (Mg), implemented via metal-organic chemical vapor deposition (MOCVD), aimed at addressing this challenge. Density-functional-theory (DFT) calculations suggest that Te incorporation could induce an intermediate band near the valence band maximum (VBM), potentially lowering the acceptor ionization barrier for Mg impurities. Initial experimental results indicate encouraging transport properties: the optimized Te-Mg co-doped thin film showed a room-temperature resistivity as low as 32.4 Ω·cm, with a measured Hall hole concentration of 1.78 × 10¹⁷ cm⁻³ and mobility of up to 5.29 cm²/V·s at lower carrier concentrations (5.72 × 10¹⁴ cm⁻³). Characterizations reveal evidence of VBM elevation via Te-Ga orbital hybridization and suggest a shift in the Fermi-level toward the valence band compatible with p-type behavior. While these preliminary findings show promise for enabling p-type Ga₂O₃ homoepitaxy, further research is necessary to optimize carrier concentrations below 1 Ω·cm, fully elucidate the Te-Mg doping dynamics, and provide more comprehensive device-level validation. This work introduces a pathway worthy of further exploration for achieving p-type conductivity in this critical semiconductor.