In this paper, using CsMA₂Sn₂I₇ as an example, first-principles calculations are performed to thoroughly investigate the crystal structures, electronic properties, and optical properties of 11 representative anchoring group/low-dimensional hybrid perovskite systems. The results show that the addition of benzene, 4-iodoaniline, aniline, and benzenethiol anchoring groups causes a blueshift phenomenon in the absorption spectra of CsMA₂Sn₂I₇ perovskite. Furthermore, the involvement of the benzoic acid anchoring group has a minimal effect on the absorption spectra of the CsMA₂Sn₂I₇ hybrid perovskites, which show better absorption intensity only in the ultraviolet. The addition of other anchoring groups leads to varying degrees of redshift in the absorption spectra of CsMA₂Sn₂I₇ perovskite, which not only enhances absorption intensity but also lends to the improvement of the absorption efficiency in the visible range. In addition, the bandgap can be tuned by applying biaxial strain, which further effectively modulates the absorption intensity of the adsorption systems in different optical bands. Therefore, the selection of suitable anchoring groups has great potential for modulating the photovoltaic performance of organic–inorganic hybrid perovskites, which is helpful for the application of organic–inorganic perovskites in photovoltaics.

中文翻译：

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利用锚定基团和双轴应变调制低维杂化钙钛矿的光学性质：第一性原理研究

本文以CsMA ₂ Sn ₂ I ₇为例，通过第一性原理计算，深入研究了11种代表性锚定基团/低维杂化钙钛矿体系的晶体结构、电子性质和光学性质。结果表明，苯、4-碘苯胺、苯胺和苯硫醇锚定基团的添加导致CsMA ₂ Sn ₂ I ₇钙钛矿的吸收光谱出现蓝移现象。此外，苯甲酸锚定基团的参与对CsMA ₂ Sn ₂ I ₇杂化钙钛矿的吸收光谱影响最小，仅在紫外区表现出更好的吸收强度。其他锚定基团的加入导致CsMA ₂ Sn ₂ I ₇钙钛矿的吸收光谱发生不同程度的红移，这不仅增强了吸收强度，而且有助于提高可见光范围内的吸收效率。此外，可以通过施加双轴应变来调节带隙，这进一步有效地调制了吸附系统在不同光波段的吸收强度。因此，选择合适的锚定基团对于调节有机-无机杂化钙钛矿的光伏性能具有巨大的潜力，有助于有机-无机钙钛矿在光伏领域的应用。