November 19 (Renewables Now) - A team of researchers at the University of Cambridge discovered that perovskite materials for solar cells and LEDs are more efficient “when their chemical compositions are less ordered”.
The scientists were surprised to see that the efficiency of the materials grew when they used rough, multi-component alloyed preparations, creating many areas with different compositions to trap the energised charge carriers.
“It is actually because of this crude processing and subsequent de-mixing of the chemical components that you create these valleys and mountains in energy that charges can funnel down and concentrate in,” said Sascha Feldmann, a PhD student at Cambridge’s Cavendish Laboratory.
Up to now, scientists assumed that efficiency will be improving as the materials get more ordered. The new findings, published in Nature Photonics, mean that simpler and cheaper manufacturing methods may give better results for perovskites.
“It is now an exciting challenge to find fabrication conditions which create the optimum disorder in the materials to achieve maximum efficiency, while still retaining the structural properties needed for specific applications,” said Dr Felix Deschler, who is leading the collaborative project together with Dr Sam Stranks.
The team at the University of Cambridge is also investigating ways to improve the stability of perovskite materials when it comes to moisture exposure.