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Delayed electron-hole recombination in a pseudo-direct semiconductor.
Nature · · Journal Article · Open access
Righetto, Banerjee + more
Abstract ↗AI summary
The abstract is read at the publisher; the summary is JClub's.
Bismuth sulfide (Bi2S3) is shown to have a pseudo-direct bandgap, with a lower-energy indirect transition paired with a direct transition a few kBT above.
- Why it matters: Reciprocity between absorptivity and emissivity limits semiconductor solar energy conversion, so breaking this constraint requires materials that decouple absorption from fast recombination.
- What they did: The authors determine the pseudo-direct bandgap character of Bi2S3 and then measure how this band structure retards bimolecular electron-hole recombination versus classic direct semiconductors.
- The result: Delayed bimolecular electron-hole recombination, combined with a high absorption coefficient, suggests an unprecedented route to overcome Planck’s law–related limitations for solar energy conversion.
The findingWhy it mattersWhat they didThe result
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