Adding the protein bacteriorhodopsin (bR) to a perovskite solar cell boosted the efficiency of the devices in a series of laboratory tests, according to the researchers from the University of Lappeenranta, Finland, and Penn State.
"These findings open the door for the development of a cheaper, more environmentally friendly bioperovskite solar cell technology," said Shashank Priya, associate vice president for research and professor of materials science at Penn State. "In the future, we may essentially replace some expensive chemicals inside solar cells with relatively cheaper natural materials."
Perovskite solar cell technology is an area of intense research as it offers a more efficient, less expensive and flexible alternative to traditional mono and poly-crystalline silicon solar cells. Currently perovskite solar cell efficiency is at 22 to 23 percent, and the researchers found that adding the bR protein to perovskite solar cells improved the devices' efficiency from 14.5 to 17 percent.
The researchers say this is the first time biological materials have been added to a perovskite solar cell to boost efficiency. Future research could result in even more efficient bioperovskite materials, the researchers said.
"Previous studies have achieved 8 or 9 percent efficiency by mixing certain proteins inside solar cell structures," said Priya, a co-lead author of the study. "But nothing has come close to 17 percent. These findings are very significant."
The researchers sought to further improve the performance of perovskite solar cells through Förster Resonance Energy Transfer (FRET), a mechanism for energy transfer between a pair of photosensitive molecules.
"The FRET mechanism has been around for a long time," said Renugopalakrishnan Venkatesan, professor at Northeastern University and Boston Children's Hospital, Harvard University. "It seems to be the basis of photosynthesis and can be found in technologies like the wireless transfer of energy, and even in the animal world as a mechanism for communication."