Biomaterial Database

Compositional texture engineering for highly stable wide-bandgap perovskite solar cells. 2022

Qi Jiang, and Jinhui Tong, and Rebecca A Scheidt, and Xiaoming Wang, and Amy E Louks, and Yeming Xian, and Robert Tirawat, and Axel F Palmstrom, and Matthew P Hautzinger, and Steven P Harvey, and Steve Johnston, and Laura T Schelhas, and Bryon W Larson, and Emily L Warren, and Matthew C Beard, and Joseph J Berry, and Yanfa Yan, and Kai Zhu

Chemistry and Nanoscience Center, National Renewable Energy Laboratory, Golden, CO 80401, USA.

The development of highly stable and efficient wide-bandgap (WBG) perovskite solar cells (PSCs) based on bromine-iodine (Br-I) mixed-halide perovskite (with Br greater than 20%) is critical to create tandem solar cells. However, issues with Br-I phase segregation under solar cell operational conditions (such as light and heat) limit the device voltage and operational stability. This challenge is often exacerbated by the ready defect formation associated with the rapid crystallization of Br-rich perovskite chemistry with antisolvent processes. We combined the rapid Br crystallization with a gentle gas-quench method to prepare highly textured columnar 1.75-electron volt Br-I mixed WBG perovskite films with reduced defect density. With this approach, we obtained 1.75-electron volt WBG PSCs with greater than 20% power conversion efficiency, approximately 1.33-volt open-circuit voltage (Voc), and excellent operational stability (less than 5% degradation over 1100 hours of operation under 1.2 sun at 65°C). When further integrated with 1.25-electron volt narrow-bandgap PSC, we obtained a 27.1% efficient, all-perovskite, two-terminal tandem device with a high Voc of 2.2 volts.