Efficient and Stable Perovskite Solar Cell with High Open-Circuit Voltage by Dimensional Interface Modification

• Published in: ACS applied materials & interfaces Vol. 11; no. 9; pp. 9149 - 9155
• Main Authors: Luo, Wei, Wu, Cuncun, Wang, Duo, Zhang, Yuqing, Zhang, Zehao, Qi, Xin, Zhu, Ning, Guo, Xuan, Qu, Bo, Xiao, Lixin, Chen, Zhijian
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 06-03-2019
• Subjects: perovskite solar cell; ambient stability; energy level modification; high open-circuit voltage; dimensional interface engineering; defect passivation
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.8b22040

High-efficiency organic–inorganic hybrid perovskite solar cells have experienced rapid development and attracted significant attention in recent years. However, instability to an ambient environment such as moisture is a facile challenge for the application of perovskite solar cells. Herein, 1,8-octanediammonium iodide (ODAI) is employed to construct a two-dimensional modified interface by in situ combined with residual PbI2 on the formamidinium lead iodide (FAPbI3) perovskite surface. The ODA2+ ion seems to lie horizontally on the surface of a three-dimensional perovskite due to its substitution for two FA+ ions, which could protect the bulk perovskite more effectively. The unencapsulated perovskite solar cells showed notably improved stability, which remained 92% of its initial efficiency after storing in an ambient environment for 120 days. In addition, a higher open-circuit voltage of 1.13 V compared to that of the control device (1.04 V) was obtained due to the interface energy level modification and defect passivation. A champion power conversion efficiency of 21.18% was therefore obtained with a stabilized power output of 20.64% at the maximum power point for planar perovskite solar cells.