Long carrier diffusion length in two-dimensional lead halide perovskite single crystals
Long carrier diffusion length in two-dimensional lead halide perovskite single crystals
复制标题
二维卤化铅钙钛矿单晶中的长载流子扩散长度
DOI：
10.1016/j.chempr.2022.01.008
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发表时间：
2022
期刊：
影响因子：
23.5
通讯作者：
Ma, Xuedan
中科院分区：
文献类型：
--
作者：
Shrestha, Shreetu;Li, Xinxin;Tsai, Hsinhan;Hou, Cheng-Hung;Huang, Hsin-Hsiang;Ghosh, Dibyajyoti;Shyue, Jing-Jong;Wang, Leeyih;Tretiak, Sergei;Ma, Xuedan
Ruddlesden-Popper(RP)钙钛矿是用于高性能光电子器件的二维半导体材料。在这项工作中，我们报道了用扫描光电流显微镜探测到的2D钙钛矿单晶中长的面内载流子扩散长度。当有机间隔体之间的PbI_6-μ_2八面体数目从1个增加到3个时，观察到的长扩散长度为7-14−m。通过详细的光强和依赖于电场的光电流测量，我们将观察到的长扩散长度归因于主要的解离自由载流子输运。时间分辨光致发光测量进一步证实了这一点，在电场存在的情况下，衰减寿命增加。实验表明，由于部分自由载流子的产生，克服了强激子效应，RP钙钛矿中的面内输运是有效的。我们的结果表明，用RP钙钛矿单晶制作的半导体器件可以和3D器件一样高效。
Ruddlesden-Popper (RP) perovskites are two-dimensional semiconductors for high-performance optoelectronic devices. In this work, we report a long in-plane carrier diffusion length in 2D RP perovskite single crystals probed by scanning photocurrent microscopy. Carrier diffusion lengths of 7–14 μm are observed when the number of PbI6−2octahedra between organic spacers increases from 1 to 3. Using detailed light intensity and electric-field-dependent photocurrent measurements, we attribute the observed long diffusion length to the dominating dissociated free carrier transport. This is further validated by time-resolved photoluminescence measurements, where the decay lifetime increases in the presence of an electric field. From our experiments, we conclude that the in-plane transport in RP perovskites is efficient because of the partial free carrier generation, which overcomes strong excitonic effects. Our results suggest that semiconducting devices fabricated from RP perovskite single crystals can be as efficient as their 3D counterparts.