Uncovering Transport Mechanisms in Perovskite Materials and Devices with Recombination-Induced Action Spectroscopies
Uncovering Transport Mechanisms in Perovskite Materials and Devices with Recombination-Induced Action Spectroscopies
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DOI：
10.1021/acs.jpcc.2c08851
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发表时间：
2023-02-02
影响因子：
3.7
通讯作者：
Moran, Andrew M.
中科院分区：
文献类型：
--
作者：
McNamee, Meredith G.;Ouyang, Zhenyu;Moran, Andrew M.
虽然有价值的见解来自传统的光谱方法，理解光伏器件的操作机制，可以限制在非原位测量。例如，在瞬态吸收实验中测量的信号反映了材料中所有光激发物质的浓度和消光系数，而不管功能相关性如何。消除这样的模糊性已经激发了各种“作用光谱”技术的发展，其中直接检测光伏器件对激光脉冲序列的响应。本透视图中描述的作用光谱类别利用复合诱导的非线性来区分光伏电池活性层内的有损（荧光）和生产（光电流）过程。虽然重组过程是有问题的，在替代方法进行行动光谱，我们的实验表明，这种类型的非线性可以用来揭示纳秒时间尺度上的传输机制。层状钙钛矿量子威尔斯的混合物的应用，以证明在光伏器件的能量泛函和长程载流子漂移的签名。
Although valuable insights are derived from conventional spectroscopic approaches, the understanding of a photovoltaic device's operation mechanisms can be limited in ex situ measurements. For example, the signals measured in transient absorption experiments reflect the concentrations and extinction coefficients of all photoexcited species in a material regardless of functional relevance. Elimination of such ambiguities has motivated the development of various "action spectroscopy" techniques in which the response of a photovoltaic device to a sequence of laser pulses is directly detected. The class of action spectroscopies described in this Perspective leverages recombination-induced nonlinearities to distinguish lossy (fluorescence) and productive (photocurrent) processes within the active layers of photovoltaic cells. Although recombination processes are problematic in alternate approaches for conducting action spectroscopies, our experiments show that this type of nonlinearity can be exploited to reveal transport mechanisms on nanosecond time scales. Applications to mixtures of layered perovskite quantum wells are presented to demonstrate signatures of energy funneling and longrange carrier drift in photovoltaic devices.