Highly accurate prediction of material optical properties based on density functional theory
Highly accurate prediction of material optical properties based on density functional theory
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DOI：
10.1016/j.commatsci.2019.109315
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发表时间：
2019-07
影响因子：
3.3
通讯作者：
Mitsutoshi Nishiwaki;H. Fujiwara
中科院分区：
文献类型：
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作者：
Mitsutoshi Nishiwaki;H. Fujiwara
基于密度泛函理论的理论材料研究在上个世纪取得了突破性进展。然而，密度泛函理论计算的光学性质与实验结果吻合较差，特别是在对数尺度下比较吸收系数(α)谱时。在这项研究中，我们建立了一种替代的密度泛函方法(PHS方法)，它计算了高精度的α光谱，即使在对数尺度上也与实验光谱表现出显著的一致性。在改进的方法中，通过结合混合泛函的能量标度修正和和法则的幅度修正，利用极高密度网格的广义梯度近似(GGA)估计的光学函数被蓝移。这种简单的方法能够高精度地预测所研究的所有太阳电池材料(砷化镓、铟磷、镉、铜铟硒和铜锌硒)的α光谱。该方法同时满足了高精度和低计算量的要求，优于传统的GGA方法、混合泛函方法和GW方法。
Theoretical material investigation based on density functional theory (DFT) has been a breakthrough in the last century. Nevertheless, the optical properties calculated by DFT generally show poor agreement with experimental results particularly when the absorption-coefficient (α) spectra in logarithmic scale are compared. In this study, we have established an alternative DFT approach (PHS method) that calculates highly accurate α spectra, which show remarkable agreement with experimental spectra even in logarithmic scale. In the developed method, the optical function estimated from generalized gradient approximation (GGA) using very high-densitykmesh is blue-shifted by incorporating the energy-scale correction by a hybrid functional and the amplitude correction by sum rule. Our simple approach enables high-precision prediction of the experimental α spectra of all solar-cell materials (GaAs, InP, CdTe, CuInSe2and Cu2ZnGeSe4) investigated here. The developed method satisfies the requirements of high accuracy and low computational cost simultaneously and is superior to conventional GGA, hybrid functional and GW methods.