Chen Xiangtian, Kamat Prashant V, Janáky Csaba, Samu Gergely Ferenc
Department of Physical Chemistry and Materials Science, Interdisciplinary Excellence Centre, University of Szeged, Aradi Square 1, Szeged H-6720, Hungary.
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.
ACS Energy Lett. 2024 Jun 5;9(6):3187-3203. doi: 10.1021/acsenergylett.4c00736. eCollection 2024 Jun 14.
Understanding photophysical processes in lead halide perovskites is an important aspect of optimizing the performance of optoelectronic devices. The determination of exact charge carrier extraction rate constants remains elusive, as there is a large and persistent discrepancy in the reported absolute values. In this review, we concentrate on experimental procedures adopted in the literature to obtain kinetic estimates of charge transfer processes and limitations imposed by the spectroscopy technique employed. Time-resolved techniques (e.g., transient absorption-reflection and time-resolved photoluminescence spectroscopy) are commonly employed to probe charge transfer at perovskite/transport layer interfaces. The variation in sample preparation and measurement conditions can produce a wide dispersion of the measured kinetic parameters. The selected time window and the kinetic fitting model employed introduce additional uncertainty. We discuss here evaluation strategies that rely on multiexponential fitting protocols (regular or stretched) and show how the dispersion in the reported values for carrier transfer rate constants can be resolved.
理解卤化铅钙钛矿中的光物理过程是优化光电器件性能的一个重要方面。由于报道的绝对值存在很大且持续的差异，确切的电荷载流子提取速率常数的确定仍然难以捉摸。在这篇综述中，我们专注于文献中采用的实验程序，以获得电荷转移过程的动力学估计以及所采用光谱技术所带来的限制。时间分辨技术（例如，瞬态吸收 - 反射和时间分辨光致发光光谱）通常用于探测钙钛矿/传输层界面处的电荷转移。样品制备和测量条件的变化会导致所测量的动力学参数出现广泛的分散。所选的时间窗口和所采用的动力学拟合模型会引入额外的不确定性。我们在此讨论依赖多指数拟合协议（常规或拉伸）的评估策略，并展示如何解决报道的载流子转移速率常数数值中的分散问题。
