Abstract In this paper we present critical analysis of different points of view on interpretation of the photoluminescence (PL) decay kinetics in lead halide perovskites prepared in the form of well passivated nanocrystals (PNCs) or thin polycrystalline layers. In addition to the literature data, our own measurements are also considered. For PNCs, a strong dependence of the PL lifetimes on the type of passivating ligand was observed with a consistently high PL quantum yield. It is shown that such ligand effects, as well as a decrease in the PL lifetime with decreasing temperature, are well qualitatively explained by the phenomenological model of thermally activated delayed luminescence, in which the extension of the PL decay time with temperature occurs due to the participation of shallow non-quenching traps. In the case of thin perovskite layers, we conclude that the PL kinetics under sufficiently low excitation intensity is determined by the excitation quenching on the layer surfaces. We demonstrate that a large variety of possible PL decay kinetics for thin polycrystalline perovskite films can be modelled by means of one-dimensional diffusion equation with use of the diffusion coefficient D and surface recombination velocity S as parameters and conclude that long-lived PL kinetics are formed in case of low D and/or S values.

中文翻译：

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金属卤化物钙钛矿纳米晶体和薄多晶薄膜中光致发光衰减动力学的解释

摘要 在本文中，我们对以良好钝化纳米晶体 (PNC) 或薄多晶层形式制备的卤化铅钙钛矿中光致发光 (PL) 衰减动力学的解释的不同观点进行了批判性分析。除了文献数据，我们自己的测量也被考虑在内。对于 PNC，观察到 PL 寿命对钝化配体类型的强烈依赖性，并具有始终如一的高 PL 量子产率。结果表明，这种配体效应以及 PL 寿命随温度降低而减少，可以通过热激活延迟发光的现象学模型很好地定性解释，其中 PL 衰减时间随温度的延长而发生浅非淬火陷阱的参与。在薄钙钛矿层的情况下，我们得出结论，在足够低的激发强度下，PL 动力学是由层表面上的激发淬灭决定的。我们证明，可以通过使用扩散系数 D 和表面复合速度 S 作为参数的一维扩散方程对薄多晶钙钛矿薄膜的多种可能的 PL 衰减动力学进行建模，并得出结论，长寿命的 PL 动力学是在低 D 和/或 S 值的情况下形成。