Molecular scale understanding of local structure and its influence on solar cell performance.
Significance and Impact
Linking local structure to solar properties enables directed design of more efficient materials.
- Organo-lead halide perovskites are mixed organic-inorganic materials with great promise for solar cells. Their band gap (thus photovoltage) can be tuned by mixing halide composition (e.g. iodide/bromide).
- We combined high-resolution X-ray spectroscopy and theory to probe local structure around lead sites in mixed I/Br perovskites, to understand functional-structural relationships in these materials.
- We found significant structural disorder: randomly distributed halides, and thermal distortions for all compositions that greatly increase band gaps.