论文标题
层边缘状态通过二维混合钙晶的内部电场稳定
Layer Edge States Stabilized by Internal Electric Fields in Two-dimensional Hybrid Perovskites
论文作者
论文摘要
近年来，由于其可调的带隙和激子结合能，对二维（2D）有机无机杂种钙钛矿进行了深入的探索，并且相对于三维（3D）混合钙钛矿而提高了稳定性。有令人着迷的实验观察结果表明，在2D混合钙钛矿中存在局部边缘状态，这些状态促进了极其有效的电子孔解离和较长的载体寿命。边缘状态的观察和解释并没有完全融合，这意味着边缘状态形成可能有多个起源。使用第一原理计算，我们证明了层边缘状态通过2D杂交钙钛矿中有机阳离子的极化分子比对产生的内部电场稳定，当它们是两层或更厚时。我们的研究对边缘状态的形成提供了简单的物理解释，它将为设计和操纵层边缘状态的光电应用铺平道路。
Two-dimensional (2D) organic-inorganic hybrid perovskites have been intensively explored for recent years, due to their tunable band gaps and exciton binding energies, and increased stability with respect to three-dimensional (3D) hybrid perovskites. There were fascinating experimental observations suggesting the existence of localized edge states in 2D hybrid perovskites which facilitate extremely efficient electron-hole dissociation and long carrier lifetimes. The observations and explanations of the edge states are not quite converging implying that there can be multiple origins for the edge state formation. Using first principles calculations, we demonstrate that layer edge states are stabilized by internal electric fields created by polarized molecular alignment of organic cations in 2D hybrid perovskites when they are two layers or thicker. Our study gives a simple physical explanation of the edge state formation, and it will pave the way for designing and manipulating layer edge states for optoelectronic applications.
