Boosting Photovoltaic Performance for Lead Halide Perovskites Solar Cells with BF4− Anion Substitutions
Abstract
Composition engineering is a particularly simple and effective approach especially using mixed cations and halide anions to optimize the morphology, crystallinity, and light absorption of perovskite films. However, there are very few reports on the use of anion substitutions to develop uniform and highly crystalline perovskite films with large grain size and reduced defects. Here, the first report of employing tetrafluoroborate (BF4−) anion substitutions to improve the properties of (FA = formamidinium, MA = methylammonium (FAPbI3)0.83(MAPbBr3)0.17) perovskite films is demonstrated. The BF4− can be successfully incorporated into a mixed‐ion perovskite crystal frame, leading to lattice relaxation and a longer photoluminescence lifetime, higher recombination resistance, and 1–2 orders magnitude lower trap density in prepared perovskite films and derived solar cells. These advantages benefit the performance of perovskite solar cells (PVSCs), resulting in an improved power conversion efficiency (PCE) of 20.16% from 17.55% due to enhanced open‐circuit voltage (VOC) and fill factor. This is the highest PCE for BF4− anion substituted lead halide PVSCs reported to date. This work provides insight for further exploration of anion substitutions in perovskites to enhance the performance of PVSCs and other optoelectronic devices.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 14, 2019
- Source ID
- 10.1002/adfm.201808833
Entities
People
- Alex K.‐y. Jen
- Jie Zhang
- Shengfan Wu
- Tiantian Liu
- Zonglong Zhu
Organizations
- City University of Hong Kong
- National Science Foundation
- Office of Naval Research
- United States Department of Energy
- University of Washington