Luo Bingcheng, Yao Yuan, Tian Enke, Shen Kun, Song Hongzhou, Song Haifeng, Li Baiwen
School of Science , China University of Geosciences , Beijing 100083 , P. R. China.
Department of Engineering , University of Cambridge , Cambridge CB3 0FA , United Kingdom.
J Phys Chem Lett. 2019 Sep 19;10(18):5609-5616. doi: 10.1021/acs.jpclett.9b02101. Epub 2019 Sep 6.
Interface engineering of halide perovskite solar-cell device layers has been showing potential for the enhancement of efficiency and stability. The replacement of spiro-OMeTAD with cheap hole extraction layer CuSCN has emerged as one effective method for the long-term large-scale application. To clarify the interfacial mechanism between the halide perovskite layer and the CuSCN layer, first-principles calculations were performed. An interface-induced electrostatic potential increase and electron-hole excitation were observed at the interfaces. A Cu-I bond and a Pb-N bond were formed at the interface. The MAI interface exhibited a larger ionic displacement and a higher interface-induced potential than the PbI interface. Strong hybridization among Cu 4d, I 5p, N 2p, and Pb 6p orbitals at the interface was found to be the origin of the electron-hole excitation, interface reconstruction, electron charge redistribution, and stability enhancement.
卤化物钙钛矿太阳能电池器件层的界面工程在提高效率和稳定性方面已显示出潜力。用廉价的空穴提取层CuSCN替代螺环-OMeTAD已成为长期大规模应用的一种有效方法。为了阐明卤化物钙钛矿层与CuSCN层之间的界面机制，进行了第一性原理计算。在界面处观察到界面诱导的静电势增加和电子-空穴激发。在界面处形成了Cu-I键和Pb-N键。MAI界面比PbI界面表现出更大的离子位移和更高的界面诱导电势。发现界面处Cu 4d、I 5p、N 2p和Pb 6p轨道之间的强杂化是电子-空穴激发、界面重构、电子电荷重新分布和稳定性增强的根源。
