In recent years, two-dimensional (2D) layered perovskites, have aroused considerable research interest due to their structural tunability and more stability compared to their 3D counterparts. The presence of long-chain organic cations strongly increases the stability of 2D perovskites. The electronic and optical properties of materials, as important parameters, can significantly affect the function of optoelectronic devices. In this paper, the electronic and optical properties of two-dimensional (2D) layered perovskite materials were studied due to their growing application in optoelectronic devices. The band structure, exciton binding energy, dielectric function, optical conductivity, absorption, and reflection spectra of a 2D (OCA) (MA)_n−1 Pb_n Br_3n+1 (n = 1, 2, 3) perovskite with Dion–Jacobson structure compared with (BA)₂ (MA)_n−1 Pb_n Br_3n+1 (n = 1, 2, 3) with Ruddlesden–Popper structure were calculated by density functional theory (DFT) method. We observed that by increasing the number of inorganic sheets, n, the band gap, carrier effective mass, and exciton binding energy of both structures decrease and reach the value of 3D perovskite almost for n = 3 due to quantum confinement effects. The obtained results indicate that the 2D (OCA) with DJ structure has a suitable band gap, high exciton binding energy, and good high absorption in comparison to that of the 2D (BA) with RP structure. DFT calculations can help to get more insight into the experimental findings. These results can be implemented for designing and developing new 2D materials for optoelectronic devices.

近年来，二维 (2D) 层状钙钛矿由于其结构可调性和比 3D 钙钛矿更高的稳定性而引起了人们的广泛研究兴趣。长链有机阳离子的存在极大地提高了二维钙钛矿的稳定性。材料的电子和光学性能作为重要参数，可以显着影响光电器件的功能。在本文中，由于二维（2D）层状钙钛矿材料在光电器件中的应用日益广泛，因此对其电子和光学特性进行了研究。2D (OCA) (MA) _n−1 Pb _n Br _{3n+1的能带结构、激子结合能、介电函数、光电导率、吸收和反射光谱}(n = 1, 2, 3) 具有 Dion-Jacobson 结构的钙​​钛矿与 (BA) ₂ (MA) _n−1 Pb _n Br _{3n+1的比较}(n = 1, 2, 3) 的 Ruddlesden-Popper 结构通过密度泛函理论 (DFT) 方法计算。我们观察到，通过增加无机片的数量，n、两种结构的带隙、载流子有效质量和激子结合能都会降低，并且由于量子限制效应，几乎在 n = 3 时达到 3D 钙钛矿的值。结果表明，与具有RP结构的2D（BA）相比，具有DJ结构的2D（OCA）具有合适的带隙、高激子结合能和良好的高吸收性。DFT 计算有助于更深入地了解实验结果。这些结果可用于设计和开发用于光电器件的新型二维材料。