Visualizing band alignment across 2D/3D perovskite heterointerfaces of solar cells with light-modulated scanning tunneling microscopy
Visualizing band alignment across 2D/3D perovskite heterointerfaces of solar cells with light-modulated scanning tunneling microscopy
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DOI：
10.1016/j.nanoen.2021.106362
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发表时间：
2021-11
期刊：
影响因子：
17.6
通讯作者：
Po‐Cheng Huang;Shao-Ku Huang;Tingrun Lai;M. Shih;H. Hsu;Chun-Hsiang Chen;Cheng‐Chieh Lin;Chun-Hao Chiang;Chi Ying Lin;K. Tsukagoshi;Chun‐Wei Chen;Y. Chiu;S. Tsay;Ying-Chiao Wang
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文献类型：
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作者：
Po‐Cheng Huang;Shao-Ku Huang;Tingrun Lai;M. Shih;H. Hsu;Chun-Hsiang Chen;Cheng‐Chieh Lin;Chun-Hao Chiang;Chi Ying Lin;K. Tsukagoshi;Chun‐Wei Chen;Y. Chiu;S. Tsay;Ying-Chiao Wang
通过定制尺寸工程生产的具有连续上移价带的分级 2D 钙钛矿盖壳，可以有效地从 3D 钙钛矿核中提取孔。电子结构的实空间观测将充分揭示2D/3D混合钙钛矿太阳能电池（PSC）的工作机制。在这里，光调制扫描隧道显微镜首次可视化了 2D (C4H9NH3)2(CH3NH3)n-1PbnI3n+1/3D CH3NH3PbI3 堆叠钙钛矿的横截面能带排列。通过系统地分析它们的电子配置，可以在空间上解析沿垂直 3D 到 2D 方向的混合维钙钛矿能带结构。值得注意的是，2D 钙钛矿中的电场在光照条件下比在黑暗条件下更大，导致分布在 2D 和 3D 钙钛矿中的空穴和电子浓度分别增加。受益于这种电子重构，电荷复合被抑制，从而显着提升 2D/3D PSC 性能。此外，我们的方法为光电器件能级的直接局部绘图开辟了一条途径。
Graded 2D perovskite capping shells with continuously upshifting valence bands, produced by tailored dimensional engineering, can effectively extract holes from 3D perovskite cores. Real-space observation of electronic structures will fully reveal the operating mechanisms of 2D/3D hybrid perovskite solar cells (PSCs). Here, for the first time, light-modulated scanning tunneling microscopy visualizes the cross-sectional band alignment across 2D (C4H9NH3)2(CH3NH3)n-1PbnI3n+1/3D CH3NH3PbI3stacked perovskites. By systematically analyzing their electronic configuration, the mixed-dimensional perovskite band structure along the vertical 3D-to-2D direction can be spatially resolved. Remarkably, the electric field in the 2D perovskite is larger under light illumination than under dark conditions, resulting in an increase in the concentration of holes and electrons distributed in the 2D and 3D perovskites, respectively. Benefiting from this electronic reconstruction, charge recombination is suppressed, thereby significantly promoting the 2D/3D PSC performance. Moreover, our method opens an avenue for direct, local mapping of optoelectronic device energy levels.