【Others Papers】First-principles study of the hole mobility of pristine and Mg-doped Ga₂O₃ under pressure

      Researchers from the Yanshan University have published a dissertation titled "First-principles study of the hole mobility of pristine and Mg-doped Ga₂O₃ under pressure" in Materials Science in Semiconductor Processing.

Abstract

      Recently, much research effort has been denoted into the understanding of the electron transport of Ga₂O₃. However, the studies on the hole mobility of p-type Ga₂O₃ remain limited. Using density functional theory, we explored the effects of pressure on the electronic structure and hole transport properties of pristine and Mg-doped Ga₂O₃. Mg dopants can induce p-type doping and magnetic moments in both β- and α-phases of Ga₂O₃. At zero pressure, both pristine and Mg-doped β-Ga₂O₃ has a low hole mobility (μ_h) in all directions, not exceeding 3.79 cm²/(V s). Pressure alters the position of the valence band maximum and decreases the hole effective mass along the y-axis. At pressures of 40 GPa and 35 GPa, pristine and Mg-doped β-Ga₂O₃ exhibit significant increases in μ_h along the y-axis, reaching 228.7 and 180.7 cm²/(V s), respectively. This provides valuable insights into the enhancement trends of charge carriers in β-Ga₂O₃ under high-voltage conditions. At high pressure, μ_h along other axes, however, decreases to less than 1 cm²/(V s), demonstrating anisotropic hole transport in β-Ga₂O₃. In comparison, pristine and Mg-doped α-Ga₂O₃ has higher μ_h than β-phase at 0 GPa. Pressure reduces the maximum μ_h of α-Ga₂O₃ due to the reduced elastic constant and increased hole effective mass. Mg doping shifts the optimal direction for hole transport in α-phase. These results improve the understanding of the hole transport in pristine and Mg-doped Ga₂O₃ under pressures.

DOI：

https://doi.org/10.1016/j.mssp.2025.109781