Surface Restructuring of Hybrid Perovskite Crystals
Surface Restructuring of Hybrid Perovskite Crystals
复制标题
DOI：
10.1021/acsenergylett.6b00517
复制
发表时间：
2016-12-01
影响因子：
22
通讯作者：
Mohammed, Omar F.
中科院分区：
文献类型：
--
作者：
Murali, Banavoth;Dey, Sukumar;Mohammed, Omar F.
杂化钙钛矿晶体因其在光电子器件中的卓越性能而成为一类重要的半导体。这些晶体的界面结构和化学性质是器件性能的关键决定因素。不幸的是，人们对钙钛矿材料表面的内在特性知之甚少，因为复杂的微观结构、加工条件和环境条件下的水合作用等外在效应被认为会导致太阳能电池的电阻损耗和高漏电流。我们揭示了单晶原始劈裂和老化表面的固有结构和光电特性。我们确定了老化表面的表面重组（通过扫描隧道显微镜在原子尺度上可视化），导致成分和光学带隙变化以及载流子动力学、光电流和太阳能电池器件性能的退化。本文报道的见解阐明了钙钛矿太阳能电池性能和高质量表面单晶制造所涉及的关键变量，从而为其未来在高效太阳能电池中的开发铺平了道路。
Hybrid perovskite crystals have emerged as an important class of semiconductors because of their remarkable performance in optoelectronics devices. The interface structure and chemistry of these crystals are key determinants of the device's performance. Unfortunately, little is known about the intrinsic properties of the surfaces of perovskite materials because extrinsic effects, such as complex microstructures, processing conditions, and hydration under ambient conditions, are thought to cause resistive losses and high leakage current in solar cells. We reveal the intrinsic structural and optoelectronic properties of both pristinely cleaved and aged surfaces of single crystals. We identify surface restructuring on the aged surfaces (visualized on the atomic-scale by scanning tunneling microscopy) that lead to compositional and optical bandgap changes as well as degradation of carrier dynamics, photocurrent, and solar cell device performance. The insights reported herein clarify the key variables involved in the performance of perovskite-based solar cells and fabrication of high-quality surface single crystals, thus paving the way toward their future exploitation in highly efficient solar cells.