The Modulation of the Optical Properties of Low-Dimensional Hybrid Perovskite by Using Anchoring Groups and Biaxial Strain: A First-Principles Study

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. In this paper, the results show that four of the anchoring groups, benzene, 4-iodoaniline, aniline, and thiophenol, cause a blueshift in the absorption spectra of CsMA2Sn2I7 perovskite, and benzoic acid has a weak effect on the absorption spectra, whereas the rest of the anchoring groups exhibit different degrees of redshifts in the absorption spectra. image