The dielectric confinement effect plays an essential role in optoelectronic devices. Existing studies on the relationship between the dielectric confinement and the photoelectric properties are inadequate. Herein, three organic spacers with different dielectric constants are employed to tune the exciton dynamics of quasi-two-dimensional (quasi-2D) Ruddlesden–Popper perovskite films. Femtosecond transient absorption spectroscopy reveals that the small dielectric constant ligand enables a weak dynamic disorder and a large modulation depth of the coherent phonons, resulting in a more complete energy transfer and the inhibition of a trap-mediated nonradiative recombination. Additionally, the increase in the bulk-ligand dielectric constant reduces the corresponding exciton binding energy and then suppresses the Auger recombination, which is beneficial for high-luminance light-emitting diodes. This work emphasizes the importance of dielectric confinement for regulating the exciton dynamics of layered perovskites.

中文翻译：

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通过准二维钙钛矿中的介电限域效应调节激子动力学

介电限域效应在光电器件中起着至关重要的作用。现有关于介电限制与光电特性之间关系的研究还不够。在此，采用三种具有不同介电常数的有机间隔物来调节准二维（准2D）Ruddlesden-Popper钙钛矿薄膜的激子动力学。飞秒瞬态吸收光谱表明，小介电常数配体能够实现弱动态无序和相干声子的大调制深度，从而导致更完整的能量转移并抑制陷阱介导的非辐射复合。此外，体配体介电常数的增加降低了相应的激子结合能，从而抑制了俄歇复合，这有利于高亮度发光二极管。这项工作强调了介电限制对于调节层状钙钛矿激子动力学的重要性。