Urban Joanna M, Chehade Gabriel, Dyksik Mateusz, Menahem Matan, Surrente Alessandro, Trippé-Allard Gaëlle, Maude Duncan K, Garrot Damien, Yaffe Omer, Deleporte Emmanuelle, Plochocka Paulina, Baranowski Michal
UPR 3228, CNRS-UGA-UPS-INSA, Laboratoire National des Champs Magnétiques Intenses, 31400 Toulouse, France.
ENS Paris-Saclay, CNRS, CentraleSupelec, LuMIn, Université Paris-Saclay, 91405 Orsay, France.
J Phys Chem Lett. 2020 Aug 6;11(15):5830-5835. doi: 10.1021/acs.jpclett.0c01714. Epub 2020 Jul 8.
The family of 2D Ruddlesden-Popper perovskites is currently attracting great interest of the scientific community as highly promising materials for energy harvesting and light emission applications. Despite the fact that these materials are known for decades, only recently has it become apparent that their optical properties are driven by the exciton-phonon coupling, which is controlled by the organic spacers. However, the detailed mechanism of this coupling, which gives rise to complex absorption and emission spectra, is the subject of ongoing controversy. In this work we show that the particularly rich, absorption spectra of (PEA)(CHNH)PbI (where PEA stands for phenylethylammonium and = 1, 2, 3), are related to a vibronic progression of excitonic transition. In contrast to other two-dimensional perovskites, we observe a coupling to a high-energy (40 meV) phonon mode probably related to the torsional motion of the NH head of the organic spacer.
二维Ruddlesden-Popper钙钛矿家族目前作为能量收集和发光应用的极具潜力的材料，正吸引着科学界的极大兴趣。尽管这些材料已为人所知数十年，但直到最近才明显发现它们的光学性质是由激子-声子耦合驱动的，而这种耦合由有机间隔基控制。然而，这种导致复杂吸收和发射光谱的耦合的详细机制仍是一个存在争议的话题。在这项工作中，我们表明(PEA)(CHNH)PbI（其中PEA代表苯乙铵，且 = 1、2、3）特别丰富的吸收光谱与激子跃迁的振动电子跃迁有关。与其他二维钙钛矿不同，我们观察到与一种高能（40毫电子伏）声子模式的耦合，这可能与有机间隔基NH头部的扭转运动有关。
