Towards Efficient and Stable All-Perovskite Tandem Solar Cells
| Date/Time: | Wednesday, 25 Sep 2019 from 4:10 pm to 5:00 pm |
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| Location: | Physics 18/19 |
| Phone: | 515-294-7377 |
| Channel: | College of Liberal Arts and Sciences |
| Actions: | Download iCal/vCal | Email Reminder |
The low-temperature solution processability and bandgap tunability make the metal halide perovskites an ideal candidate for fabricating all-perovskite tandem solar cells, which can overcome the Shockley-Queisser (SQ) radiative efficiency limits for single-junction cells. However, the lack of high-quality low-bandgap perovskite absorber layers seriously hampers the development of efficient and stable two-terminal monolithic all-perovskite tandem solar cells. In this talk, we report our strategies for producing high quality mixed tin-lead low-bandgap (~1.25 eV) perovskite absorber layers. The improved electronic properties enabled us to fabricate efficient low-bandgap perovskite solar cells using thick absorber layers, which is a requisite for efficient tandem solar cells. With such improvement, we were able to fabricate efficient two-terminal and four-terminal all-perovskite tandem solar cells with a champion power conversion efficiency of exceeding 23% and 25%, respectively. The efficiencies were retained to 85% of their initial performance after 80 hours of operation under continuous illumination.