【Substrate Papers】High-Electron-Mobility and Ultrawide-Bandgap β-(AlₓInᵧGa(₁₋ₓ₋ᵧ))₂O₃ Lattice-Matched to β-Ga₂O₃

      Researchers from Shenzhen Pinghu Laboratory have published a dissertation titled " High-Electron-Mobility and Ultrawide-Bandgap β-(Al_xIn_yGa_1−x−y)₂O₃ Lattice-Matched to β-Ga₂O₃ " in Journal of Electronic Materials.

Abstract

      Maintaining a wide bandgap while enhancing electron mobility is crucial for advancing the performance of β-Ga₂O₃-based power devices. Herein, the structural and electronic properties of quaternary β-(Al_xIn_yGa_1−x−y)₂O₃ (0 ≤ x ≤ 0.09375; 0 ≤ y ≤ 0.09375; x−y ≤ −0.03125) are studied via first-principles calculations. Given its predicted minimal lattice mismatch of less than 1.09% with β-Ga₂O₃, β-(Al_xIn_yGa_1−x−y)₂O₃ can be epitaxially grown on β-Ga₂O₃ substrates. The bandgaps of β-(Al_xIn_yGa_1−x−y)₂O₃ are calculated and fitted to the function of gap = 1.82x − 1.80y − 8.32x⋅y + 4.81, with all values determined to exceed 4.68 eV. Notably, β-(Al_xIn_yGa_1−x−y)₂O₃ exhibits high and anisotropic electron mobility. At an electron concentration of 10¹⁶ cm⁻³, the average electron mobility of β-(Al_0.0625In_0.09375Ga_0.84375)₂O₃ reaches 501 cm²V⁻¹s⁻¹, which is 3.98 times that of β-Ga₂O₃. Specifically, the electron mobility along the b-axis of β-(Al_xIn_yGa_1−x−y)₂O₃ is consistently higher, and room-temperature mobility of 1153 cm²V⁻¹s⁻¹ is achieved for a β-(Al_0.0625In_0.09375Ga_0.84375)₂O₃ configuration. The high electron mobility is attributed to the delocalized nature of the In 5s orbital, which makes a greater contribution to the conduction band minimum of β-(Al_xIn_yGa_1−x−y)₂O₃. The anisotropy of electron mobility in β-(Al_xIn_yGa_1−x−y)₂O₃ strongly depends on the distribution of In atoms, and the higher mobility values along the b-axis are due to the more compact atomic arrangement in this direction. Our results suggest that β-(Al_xIn_yGa_1−x−y)₂O₃ holds significant potential for high-power device applications.

DOI：

https://doi.org/10.1007/s11664-026-12904-z