Liu Diwen, Huang Shuyun, Wang Xianzhong, Sa Rongjian
School of Materials and Chemical Engineering, Pingxiang University, Pingxiang 337055, China.
School of Materials and Chemical Engineering, Pingxiang University, Pingxiang 337055, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Apr 5;250:119389. doi: 10.1016/j.saa.2020.119389. Epub 2020 Dec 29.
NaSbS has been proposed as a novel photovoltaic material, but its band gap is not suitable for single-junction solar cells. In the present study, the systematic first-principles calculations were carried out to investigate the structural, mechanical, electronic and optical properties of ASbS (A = Li, Na, K) and NaLiSbS solid solutions. These structures show good structural stability compared to CHNHPbI. The results indicate that all the structures are indirect band gap semiconductors. The band gap of ASbS increases gradually when the alkali metal changes from Li to K. The band gap of NaSbS can be tuned by manipulating the amount of Li doping. The NaLiSbS solid solutions have suitable band gaps for light-absorber semiconductors in solar cells. Moreover, the suitable band gap of NaSbS can be also obtained under moderate pressure. The mechanical properties of these materials are also analyzed, and the results indicate that they are brittle materials except for KSbS. The optical absorption coefficients of these compounds are large over 10 cm in the visible light region. We find that alloying can provide a feasible and effective approach for improving the photovoltaic performance of NaSbS-based solar cells.
硫代锑酸钠已被提议作为一种新型光伏材料，但其带隙不适合单结太阳能电池。在本研究中，进行了系统的第一性原理计算，以研究硫代锑酸A（A = 锂、钠、钾）和硫代锑酸锂钠固溶体的结构、力学、电子和光学性质。与CHNHPbI相比，这些结构显示出良好的结构稳定性。结果表明，所有结构均为间接带隙半导体。当碱金属从锂变为钾时，硫代锑酸A的带隙逐渐增大。硫代锑酸钠的带隙可通过控制锂掺杂量来调节。硫代锑酸锂钠固溶体具有适合太阳能电池中光吸收半导体的带隙。此外，在中等压力下也可获得硫代锑酸钠合适的带隙。还分析了这些材料的力学性能，结果表明除了硫代锑酸钾外，它们都是脆性材料。这些化合物在可见光区域的光吸收系数大于10⁵ cm⁻¹。我们发现合金化可为提高硫代锑酸钠基太阳能电池的光伏性能提供一种可行且有效的方法。
