Based on the density functional theory, the energy band and electronic structure of β-CuGaO2 are calculated by the modified Becke-Johnson plus an on-site Coulomb U (MBJ + U) approach in this paper. The calculated results show that the band gap value of β-CuGaO2 obtained by the MBJ + U approach is close to the experimental value. The calculated results of electronic structure indicate that the main properties of the material are determined by the bond between Cu-3d and O-2p energy levels near the valence band of β-CuGaO2, while a weak anti-bond combination is formed mainly by the O-2p energy level and Ga-4s energy level near the bottom of the conduction band of β-CuGaO2. The β-CuGaO2 thin film is predicted to hold excellent photovoltaic performance by analysis of the spectroscopic limited maximum efficiency (SLME) method. At the same time, the calculated maximum photoelectric conversion efficiency of the ideal CuGaO2 solar cell is 32.4%. Relevant conclusions can expand β-CuGaO2 photovoltaic applications.

中文翻译：

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MBJ+U方法对β-CuGaO2电子结构和光伏特性的第一性原理研究

本文基于密度泛函理论，通过改进的Becke-Johnson加上现场Coulomb U (MBJ + U)方法计算了β-CuGaO2的能带和电子结构。计算结果表明，MBJ+U方法得到的β-CuGaO2的带隙值与实验值接近。电子结构的计算结果表明，材料的主要性能由 β-CuGaO2 价带附近的 Cu-3d 和 O-2p 能级之间的键决定，而弱反键组合主要由β-CuGaO2 导带底部附近的 O-2p 能级和 Ga-4s 能级。通过对光谱有限最大效率（SLME）方法的分析，预测 β-CuGaO2 薄膜具有优异的光伏性能。同时，计算出的理想 CuGaO2 太阳能电池的最大光电转换效率为 32.4%。相关结论可以拓展β-CuGaO2光伏应用。