Relationship between the Nature of Monovalent Cations and Charge Recombination in Metal Halide Perovskites
We report charge recombination rates in lead iodide perovskites with alloys of formamidinium (FA) and methylammonium (MA) cations, FAxMA1–xPbI3, 0 ≤ x ≤ 0.9, prepared through ion exchange with minimal differences in morphology and charge trap density. Our results show that the trap-mediated recombination rate increases over 2 orders of magnitude with decreasing MA content. These results are consistent with a proposed mechanism that MA molecules are more effective in screening charged defects. In contrast, band-to-band charge recombination rates are minimized at an intermediate alloy composition. Here, these findings reveal that the monovalent cations impact recombination processes through different mechanisms.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1606703
- Journal Information:
- ACS Applied Energy Materials, Journal Name: ACS Applied Energy Materials Journal Issue: 2 Vol. 3; ISSN 2574-0962
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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