Abstract
Light-induced phase segregation poses challenges for the application of mixed-halide hybrid perovskites in photovoltaics, causing voltage deficits. Here, we investigate the role of chemical composition in improving the photostability of wide bandgap mixed-halide perovskites. We partially substituted the formamidinium cation in the composition of (Cs0.17FA0.83)Pb(Br0.2I0.8)3 with seven alternative cations to achieve a slight blue shift in the bandgap, typically achieved by increasing bromide content. Among alternative cations, dimethylammonium (DMA) and acetamidinium (Ac) induced greater blue shifts at 10% concentration without forming a new low-dimensional second phase. Photoluminescence studies, which analyzed the halide segregation induced by high-power laser irradiation of all new compositions, revealed reduced phase segregation for DMA and Ac compositions. Further adjustments, e.g., increased cesium content, effectively compensated for the lower bromide content in the bandgap while enhancing light stability. Among all compositions, Cs0.25FA0.65DMA0.1Pb(Br0.2I0.8)3 exhibited enhanced photostability. These findings highlight the potential of structural modifications to produce highly stable compositions with the desired bandgap, paving the way for the development of stable perovskite solar cells.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3400-3408 |
| Number of pages | 9 |
| Journal | ACS Energy Letters |
| Volume | 9 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 12 2024 |
Funding
This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under award number DE-SC-0024422 (synthesis and fundamental studies of metal halides. We acknowledge the financial support from the Swedish Research Council for Sustainable Development-Formas (2017-01134) through their \u201CMobility Starting Grant\u201D program, which enabled M. S. to be a visiting scholar at Northwestern University, USA. A.B. was supported by a fellowship through the National Defense Science and Engineering Graduate Fellowship Program (NDSEG), sponsored by the Air Force Research Laboratory (AFRL), Office of Naval Research (ONR), and Army Research Office (ARO). The UV\u2013vis experiments presented in this study utilized the IMSERC Crystallographic and Physical Characterization facilities at Northwestern University, which were supported by the Soft and Hybrid Nanotechnology Experimental (SHyNE) resource (NSF ECCS-2025633) and Northwestern University. SEM data were gathered at the EPIC facility within the NUANCE Center of Northwestern University, which has received support from the SHyNE resource, the IIN, and Northwestern\u2019s MRSEC program (NSF DMR-1720139). The authors also thank Dr. Christos D. Milliakas and Dr. Seung Won Lee for their insights.
ASJC Scopus subject areas
- Chemistry (miscellaneous)
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Energy Engineering and Power Technology
- Materials Chemistry
