Led by the Department of Energy’s Oak Ridge National Laboratory and the University of Tennessee, Knoxville, a study of a solar-energy material with a bright future revealed a way to slow phonons, the waves that transport heat. The discovery could improve novel hot-carrier solar cells, which convert sunlight to electricity more efficiently than conventional solar cells by harnessing photogenerated charge carriers before they lose energy to heat.
“We showed that the thermal transport and charge-carrier cooling time can be manipulated by changing the mass of hydrogen atoms in a photovoltaic material,” said ORNL’s Michael Manley. “This route for extending the lifetime of charge carriers bares new strategies for achieving record solar-to-electric conversion efficiency in novel hot-carrier solar cells.”
UT’s Mahshid Ahmadi noted, “Tuning the organic-molecule dynamics can enable control of phonons important to thermal conductivity in organometallic perovskites.” These semiconducting materials are promising for photovoltaic applications.