The electronic structure and optoelectronic properties of Mn-doped β-Ga2O3 were studied over a wide range of dopant concentrations using the generalized gradient approximation and the Hubbard model with a “corrective potential” U (Method GGA + U) within density functional theory (DFT). The study revealed that, compared to intrinsic β-Ga2O3, Mn preferentially substituted at the octahedral Ga(2) site, leading to a monotonic lattice expansion and a reduction in the direct band gap from 4.83 eV (undoped) to 3.45 eV at 1.67 at % Mn. This band gap narrowing was attributed to hybridized Mn 3d–O 2p states, which raised the Fermi level and enhanced electrical conductivity. Across four doping configurations, increasing Mn concentration consistently reduced electron mobility from 0.307 to 0.030 m2 V–1 s–1 and suppressed conductivity by two orders of magnitude, underscoring a significant trade-off between optical enhancement and electrical performance. Conductivity peaks at 7.45 × 1022 S m–1 for the 0.83 at % Mn-doped sample, then declined to 5.76 × 1022 and 5.79 × 1021 S m–1 for the 1.00 and 1.25 at % Mn concentrations, respectively. At 1.67 at % Mn, conductivity reached its lowest value of 5.83 × 1020 S m–1, accompanied by a minimum mobility of 0.030 m2 V–1 s–1. These findings provided quantitative theoretical insights and practical guidance for optimizing doping strategies in Mn-doped β-Ga2O3 optoelectronic devices.
Li et al. (2026) studied this question.