KAUST team goes deep on perovskite physics

When light hits a perovskite, it excites negatively charged electrons and leaves behind positively-charged ‘gaps’ within the material’s crystalline structure. These electrons and gaps can then move through the perovskite to generate an electrical current. However, the charge carriers can also recombine instead, wasting the energy they carry.

“The efficiency of perovskite solar cells has been greatly improved in the past decade, but fundamental research on their photophysics is relatively backward,” said researcher Ming-Cong Wang from the KAUST Solar Centre. “One of the things that is not clear is how charge carriers behave before recombining.”

Some of the ions that make up the perovskite’s crystal lattice can help to localise electrons and gaps in different regions, which prevents them from recombining and prolongs their lives. However, this localisation also tends to make the charge carriers less mobile, which may adversely affect the solar cell’s performance. Understanding such effects could help researchers to fine-tune the composition of perovskites and boost their ability to generate electricity from sunlight.