Xiang Sisi, Li Weiping, Wei Ya, Liu Jiaming, Liu Huicong, Zhu Liqun, Yang Shihe, Chen Haining
School of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Haidian District, Beijing 100191, People's Republic of China.
Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Guangdong Key Lab of Nano-Micro Material Research, School of Chemical Biology and Biotechnology, Shenzhen Graduate School, Peking University, Shenzhen 518055, China.
iScience. 2019 May 31;15:156-164. doi: 10.1016/j.isci.2019.04.025. Epub 2019 Apr 25.
The CsPbI inorganic perovskite is a potential candidate for fabricating long-term operational photovoltaic devices owing to its intrinsic superb thermal stability. However, the carbon-based CsPbI perovskite solar cells (C-PSCs) without hole transport material (HTM) are currently disadvantaged by their relatively low power conversion efficiency resulting from the poor grain quality and mismatched energy band levels of the as-made CsPbI films. Herein we demonstrate that by doping Na into the CsPbI lattice, the grain quality is significantly improved with low defect density, and also, the energy band levels are better matched to the contact electrodes, affording a higher built-in potential. Consequently, the V of the C-PSCs is drastically increased from 0.77 to 0.92 V, and the efficiency from 8.6% to 10.7%, a record value for the CsPbI PSCs without HTM. Moreover, the non-encapsulated device showed virtually no performance degradation after 70 days of storage in air atmosphere.
由于其固有的出色热稳定性，CsPbI无机钙钛矿是制造长期运行的光伏器件的潜在候选材料。然而，目前没有空穴传输材料（HTM）的碳基CsPbI钙钛矿太阳能电池（C-PSCs）存在劣势，因为所制备的CsPbI薄膜的晶粒质量差和能带水平不匹配，导致其功率转换效率相对较低。在此，我们证明通过将Na掺杂到CsPbI晶格中，显著提高了晶粒质量，降低了缺陷密度，并且能带水平与接触电极更好地匹配，提供了更高的内建电势。因此，C-PSCs的V从0.77 V急剧增加到0.92 V，效率从8.6%提高到10.7%，这是无HTM的CsPbI PSCs的记录值。此外，未封装的器件在大气中储存70天后几乎没有性能下降。
