Jung Young-Kwang, Dubajic Milos, Stranks Samuel D
Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, U.K.
Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, U.K.
J Phys Chem Lett. 2025 Jun 12;16(23):5862-5867. doi: 10.1021/acs.jpclett.5c00814. Epub 2025 Jun 5.
Complex structural dynamics in halide perovskites have attracted researchers in the field of perovskite optoelectronics. Although state-of-the-art experimental and theoretical techniques have disclosed the dynamic nature of local tilting in halide perovskites, how such local tilting influences the physical properties of these materials is still poorly understood. In this study, we model confined local tilting within a cubic halide perovskite CsPbBr and reveal the electronic consequences of the local tilting, employing density functional theory. Our calculations confirm that the locally tilted layers have larger band gaps than the host cubic lattice, where no charge trapping levels are introduced by them. The degree of local band gap fluctuation is predicted to depend significantly on the geometry of the locally tilted domains. We conclude that local tilting will act as dynamic charge-blocking barriers, which impact carrier dynamics in perovskite optoelectronic devices.
卤化物钙钛矿中的复杂结构动力学吸引了钙钛矿光电子学领域的研究人员。尽管目前先进的实验和理论技术已经揭示了卤化物钙钛矿中局部倾斜的动态性质，但这种局部倾斜如何影响这些材料的物理性质仍知之甚少。在本研究中，我们对立方卤化物钙钛矿CsPbBr₃中的受限局部倾斜进行建模，并采用密度泛函理论揭示局部倾斜的电子效应。我们的计算证实，局部倾斜层的带隙比主体立方晶格大，且它们不会引入电荷俘获能级。预计局部带隙波动程度将显著取决于局部倾斜域的几何形状。我们得出结论，局部倾斜将充当动态电荷阻挡势垒，影响钙钛矿光电器件中的载流子动力学。
