Pazuki Mohammad Reza, Sardroodi Jaber Jahanbin, Rastegar Sima
Department of Physics, Azarbaijan Shahid Madani University, Tabriz, Iran.
Molecular Simulation Laboratory (MSL), Azarbaijan Shahid Madani University, Tabriz, Iran.
Sci Rep. 2025 Jul 23;15(1):26724. doi: 10.1038/s41598-025-11320-3.
This study investigated the physical properties of perovskite compounds with the general formula APbBr (A = K, Rb, and Cs), Applying the Density Functional Theory (DFT) method. For these APbBr crystals, the optimum lattice constants are determined, serving as the basis for the computations. In these calculations, pseudopotential by GGA-PBE correlation exchange functional is used. The band gap, Density of States (DOS), Projected Density of States (PDOS), charge density, and charge difference caused by changing the charge of each element in the primary state or the lattice constant in one and three directions are estimated. The energy gaps for KPbBr, RbPbBr, and CsPbBr for GGA-PBE pseudopotentials were 1.7436, 1.7746, and 1.7815 eV and for CsPbBr with optimized and experimental lattice constants, 1.78 eV and 1.81 eV, respectively. Also, computation results showed that in some cases (the size of the lattice constant change, for example, was 10%), there were critical points such as conductivity, topological insulator and n-type semiconductor. Finally, studying the electronic structure of these perovskite by changing the lattice constant is a new and novel method in its own right. Also the electronic structure of this perovskite by changing the lattice constant has not been considered in other studies.
本研究采用密度泛函理论（DFT）方法，研究了通式为APbBr（A = K、Rb和Cs）的钙钛矿化合物的物理性质。对于这些APbBr晶体，确定了最佳晶格常数，作为计算的基础。在这些计算中，使用了GGA-PBE关联交换泛函的赝势。估算了带隙、态密度（DOS）、投影态密度（PDOS）、电荷密度以及在基态下改变每个元素的电荷或在一个和三个方向上改变晶格常数所引起的电荷差。对于GGA-PBE赝势，KPbBr、RbPbBr和CsPbBr的能隙分别为1.7436、1.7746和1.7815 eV，对于具有优化晶格常数和实验晶格常数的CsPbBr，能隙分别为1.78 eV和1.81 eV。此外，计算结果表明，在某些情况下（例如，晶格常数变化的大小为10%），存在诸如导电性、拓扑绝缘体和n型半导体等临界点。最后，通过改变晶格常数来研究这些钙钛矿的电子结构本身就是一种新颖的方法。而且，其他研究中尚未考虑通过改变晶格常数来研究这种钙钛矿的电子结构。
