https://phys.org/news/2018-07-boost-quality-perovskites.html > In a paper published online this spring in the journal Nature Photonics, scientists at the University of Washington report that a prototype semiconductor thin-film has performed even better than today's best solar cell materials at emitting light. > "It may sound odd since solar cells absorb light and turn it into electricity, but the best solar cell materials are also great at emitting light," said co-author and UW chemical engineering professor Hugh Hillhouse, who is also a faculty member with both the UW's Clean Energy Institute and Molecular Engineering & Sciences Institute. "In fact, typically the more efficiently they emit light, the more voltage they generate."