Probing Carrier Transport in Layered Perovskites with Nonlinear Optical and Photocurrent Spectroscopies
Probing Carrier Transport in Layered Perovskites with Nonlinear Optical and Photocurrent Spectroscopies
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DOI：
10.1021/acs.jpcc.1c00654
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发表时间：
2021-04
影响因子：
3.7
通讯作者：
Ninghao Zhou;Zhenyu Ouyang;M. McNamee;Olivia F. Williams;Zhenkun Guo;Liang Yan;Jun Hu;W. You;Andrew M. Moran
中科院分区：
文献类型：
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作者：
Ninghao Zhou;Zhenyu Ouyang;M. McNamee;Olivia F. Williams;Zhenkun Guo;Liang Yan;Jun Hu;W. You;Andrew M. Moran
对层状钙钛矿量子威尔斯的兴趣是由它们在光电器件中的应用潜力所激发的。在这些系统中，最小和最大的量子威尔斯最集中在光伏电池中的相对电极附近。能级和量子阱浓度的重合梯度促进了电子激发和电荷载流子通过空间的功能。在这方面，我们描述了几种非线性光学技术的发展，旨在阐明层状钙钛矿系统中光吸收引起的弛豫过程。瞬态吸收显微镜提供了深入了解载流子扩散和两体复合过程，而二维动作光谱用于关联基本弛豫机制的光伏器件性能的实际指标。我们的实验表明，电荷载流子的funeries过程不促进远程传输由于捕获。相反，薄膜的块状相吸收光并传输载流子，而没有最小的量子威尔斯的参与。
Interest in layered perovskite quantum wells is motivated by their potential for use in optoelectronic devices. In these systems, the smallest and largest quantum wells are most concentrated near opposing electrodes in photovoltaic cells. Coincident gradients in the energy levels and quantum well concentrations promote the funneling of electronic excitations and charge carriers through space. In this Perspective, we describe the development of several nonlinear optical techniques designed to elucidate the relaxation processes induced by light absorption in layered perovskite systems. Transient absorption microscopy provides insight into carrier diffusion and two-body recombination processes, whereas two-dimensional action spectroscopies are used to correlate elementary relaxation mechanisms to practical metrics of photovoltaic device performance. Our experiments suggest that charge carrier funneling processes do not facilitate long-range transport due to trapping. Rather, the bulklike phases of the films absorb light and transport carriers without participation of the smallest quantum wells.