Electron-phonon interaction in efficient perovskite blue emitters
Electron-phonon interaction in efficient perovskite blue emitters
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DOI：
10.1038/s41563-018-0081-x
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发表时间：
2018-06-01
期刊：
影响因子：
41.2
通讯作者：
Sargent, Edward H.
中科院分区：
文献类型：
--
作者：
Gong, Xiwen;Voznyy, Oleksandr;Sargent, Edward H.
低维钙钛矿具有高的辐射复合率，在实现高发光亮度和色饱和度方面显示出巨大的前景。在这里，我们研究了电子-声子相互作用对二维钙钛矿单晶发光的影响，表明减少这些相互作用可以导致二维钙钛矿中明亮的蓝色发光。共振拉曼光谱和形变势分析表明，强的电子-声子相互作用导致快速的非辐射衰减，这降低了光致发光量子产率（PLQY）。中子散射、自旋-晶格弛豫的固态NMR测量、密度泛函理论模拟和实验原子位移测量表明，在最亮的发射体中，分子运动最慢，刚性最大。通过改变配体的分子构型，我们表明，PLQY高达79%，线宽为20 nm，可以通过控制晶体的刚性和电子-声子相互作用达到。考虑到电子-声子相互作用设计晶体结构提供了一种以前未探索的途径来改善光电材料的性能。
Low-dimensional perovskites have-in view of their high radiative recombination rates-shown great promise in achieving high luminescence brightness and colour saturation. Here we investigate the effect of electron-phonon interactions on the luminescence of single crystals of two-dimensional perovskites, showing that reducing these interactions can lead to bright blue emission in two-dimensional perovskites. Resonance Raman spectra and deformation potential analysis show that strong electron-phonon interactions result in fast non-radiative decay, and that this lowers the photoluminescence quantum yield (PLQY). Neutron scattering, solid-state NMR measurements of spin-lattice relaxation, density functional theory simulations and experimental atomic displacement measurements reveal that molecular motion is slowest, and rigidity greatest, in the brightest emitter. By varying the molecular configuration of the ligands, we show that a PLQY up to 79% and linewidth of 20 nm can be reached by controlling crystal rigidity and electron-phonon interactions. Designing crystal structures with electron-phonon interactions in mind offers a previously underexplored avenue to improve optoelectronic materials' performance.