A bandgap bowing parameter of 0.4 ± 0.2 eV for β-(Al_xGa_1−x)₂O₃ alloys, with Al compositions (x) up to 0.35, has been determined from the bandgap obtained from low temperature optical reflectivity, which suppresses the effect of electron–phonon interaction on the bandgap. A length scale of inhomogeneity of 0.21 ± 0.03 times of the electron–hole mean free path length has been estimated for β-(Al_xGa_1−x)₂O₃ alloys. The unit cell of β-(Al_xGa_1−x)₂O₃ alloys compresses, and the lattice parameters vary linearly with Al substitution. Our results provide insight into bandgap engineering and alloy disorder for β-(Al_xGa_1−x)₂O₃ alloys, which are an important material system for applications in deep ultraviolet opto-electronic devices.

中文翻译：

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β-(AlxGa1-x)2O3合金的带隙弯曲参数和合金波动x≤0.35由低温光学反射率确定

β-(Al _x Ga _{1- x} ) ₂ O ₃合金的带隙弯曲参数为 0.4 ± 0.2 eV ，Al 成分 ( x ) 高达 0.35，已从低温光学反射率获得的带隙确定，这抑制了电子-声子相互作用对带隙的影响。β-(Al _x Ga _{1- x} ) ₂ O ₃合金的非均匀性长度尺度估计为电子-空穴平均自由程长度的 0.21 ± 0.03 倍。β-(Al _x Ga _{1− x} ) ₂ O _{3 的}晶胞合金压缩，晶格参数随铝置换线性变化。我们的研究结果提供了对 β-(Al _x Ga _{1- x} ) ₂ O ₃合金带隙工程和合金无序的深入了解，β-(Al _x Ga _{1- x} ) ₂ O ₃合金是深紫外光电器件应用的重要材料系统。