Zhang Yajun, Sahoo M P K, Liang Yunting, Tang Gang
Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education of China, Lanzhou University, Lanzhou, Gansu730000, People's Republic of China.
Department of Mechanics and Engineering Sciences, College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu730000, People's Republic of China.
J Phys Chem Lett. 2022 Oct 20;13(41):9632-9641. doi: 10.1021/acs.jpclett.2c01992. Epub 2022 Oct 10.
Dimensionality engineering in ABX Ruddlesden-Popper (RP) perovskites has recently emerged as a promising tool for tuning the band gap to improve optoelectronic properties. However, the evolution of the band gap is dependent on the material; distinguishing the effects of different factors is urgently needed to guide the rational design of high-performance materials. Through first-principles calculations, we perform a systematic investigation of RP oxide, chalcogenide, and halide perovskites. The results reveal that in addition to the confinement effect and the change in octahedral rotation motions and/or amplitudes, interfacial rumpling and a change in the A-site cation coordination number also determine the evolution of the band gap. More importantly, we emphasize that the evolution of the band gap in RP perovskites is not dependent on the material family. Instead, the B-site frontier orbital type (s, p, and d) and bandwidth, A-site cation, interfacial rumpling, and structural distortions simultaneously determine the evolution of the band gap. These insights enable a complete and deeper understanding of various experimental observations.
ABX 型鲁德尔斯登-波普（RP）钙钛矿中的维度工程最近已成为一种很有前景的工具，用于调节带隙以改善光电性能。然而，带隙的演变取决于材料；迫切需要区分不同因素的影响，以指导高性能材料的合理设计。通过第一性原理计算，我们对 RP 氧化物、硫族化物和卤化物钙钛矿进行了系统研究。结果表明，除了限制效应以及八面体旋转运动和/或振幅的变化外，界面褶皱和 A 位阳离子配位数的变化也决定了带隙的演变。更重要的是，我们强调 RP 钙钛矿中带隙的演变并不取决于材料家族。相反，B 位前沿轨道类型（s、p 和 d）和带宽、A 位阳离子、界面褶皱和结构畸变同时决定了带隙的演变。这些见解有助于对各种实验观察结果有更全面和深入的理解。
