The main aim of this work is to determine and explain the relationships between optoelectronic properties and the sulfur anion content in Cu₂ZnSn(S_xSe_1−x)₄ solid solution. Band gap and absorption coefficient are of primary interest to the engineers and scientists researcher worked in optoelectronic field. Herein, the electronic and optical properties are calculated based on 128 conventional atoms within lattice parameters obtained at 300 K by using the FP-LAPW method combined with quasi-harmonic Debye model. The composition dependent band gaps of CZTSSe solid solutions are investigated by TB-mBJ+U. As results, all materials are semiconductors with a direct band gap ranging from 0.614 to 0.99 eV. The band gap variation increases as a function of sulfur anion content and showed a positive deviation from Vegard's law with a very small downward bowing parameter of + 0.079 eV. The density of state (DOS) calculations indicate that the energy bands of VBM involve Cu_d/anion(S/Se)_p hybridized antibonding-like states. Based on band alignment, the Ec offset between CZTS and CZTSe is larger than the Ev offset. These results are reported previously in other work and are confirmed in this study. Our work included a systematic comparison of the influence of S/(S+Se) atomic ratios on optical quantities. The dielectric function tensors show remarkable anisotropy. In addition, the static dielectric constants are found to decrease with sulfur anion content. The CZTSSe is proved to be suitable for good solar cells with high absorption coefficient (> 10⁴ cm⁻¹). Such deep optical studies would be helpful for future optoelectronic applications of these compounds with different S/(S+Se) atomic ratios.

这项工作的主要目的是确定和解释光电特性与 Cu ₂ ZnSn(S _x Se _1-x ) _{4 中}硫阴离子含量之间的关系实在的方法。带隙和吸收系数是在光电领域工作的工程师和科学家研究人员的主要兴趣。在此，使用FP-LAPW方法结合准谐波德拜模型，基于300 K获得的晶格参数内的128个常规原子计算电子和光学性质。通过 TB-mBJ+U 研究了 CZTSSe 固溶体的组成相关带隙。结果，所有材料都是直接带隙范围为 0.614 到 0.99 eV 的半导体。带隙变化作为硫阴离子含量的函数而增加，并显示出与 Vegard 定律的正偏差，向下弯曲参数非常小，为 + 0.079 eV。态密度 (DOS) 计算表明 VBM 的能带涉及 Cu_d/anion(S/Se)_p 杂化反键合状态。基于波段对齐，CZTS 和 CZTSe 之间的 Ec 偏移量大于 Ev 偏移量。这些结果以前在其他工作中报告过，并在本研究中得到证实。我们的工作包括系统比较 S/(S+Se) 原子比对光学量的影响。介电函数张量表现出显着的各向异性。此外，发现静态介电常数随硫阴离子含量而降低。CZTSSe 被证明适用于具有高吸收系数（> 10 这些结果以前在其他工作中报告过，并在本研究中得到证实。我们的工作包括系统比较 S/(S+Se) 原子比对光学量的影响。介电函数张量表现出显着的各向异性。此外，发现静态介电常数随硫阴离子含量而降低。CZTSSe 被证明适用于具有高吸收系数（> 10 这些结果以前在其他工作中报告过，并在本研究中得到证实。我们的工作包括系统比较 S/(S+Se) 原子比对光学量的影响。介电函数张量表现出显着的各向异性。此外，发现静态介电常数随硫阴离子含量而降低。CZTSSe 被证明适用于具有高吸收系数 (> 10⁴厘米^-1 )。这种深入的光学研究将有助于这些具有不同 S/(S+Se) 原子比的化合物的未来光电应用。