Increasing perovskite solar cell efficiency
Researchers at The Australian National University (ANU) say they have broken their own record to create a more efficient solar cell, with the results of their breakthrough published in the journal Nature.
The team’s study focused on 1 cm2 solar cells made with perovskites — a family of materials with a specific crystal structure. Perovskite solar cells have the potential to be made more cheaply and simply than other solar cells, as well as to produce more power in a given area; but conversion efficiencies are limited by a fill factor — one measure of the quality of the solar cell — of less than 83%.
“This limitation results from non-ideal charge transport between the perovskite absorber and the cell’s electrodes,” the study authors wrote. “Reducing the electrical series resistance of charge transport layers is therefore crucial for improving efficiency.”
To solve this problem, the researchers used standard fabrication techniques but applied them to a new material — titanium oxynitride — to create perovskite solar cells in a unique way. As published in the study, they introduced “a reverse-doping process to fabricate nitrogen-doped titanium oxide electron transport layers with outstanding charge transport performance”.
By incorporating this charge transport material into perovskite solar cells, the team demonstrated 1 cm2 cells with fill factors of >86%, and an average fill factor of 85.3%. They also achieved a certified steady-state efficiency of 22.6% for a 1 cm2 cell, meaning the cells can convert 22.6% of sunlight into energy.
The researchers say the solar cells they have produced are cheap and easy to manufacture, in addition to achieving high efficiency, while using an approach that is different to what has been done previously.
“We’ve also been able to overcome an energy loss in one of the layers that scientists didn’t previously realise was there,” said Professor Kylie Catchpole, co-author on the study.
“The modelling we’ve done shows this was a limitation in previous types of solar cells.”
Engineers from RMIT University are experimenting with an innovation that uses high-frequency...
Researchers at Argonne National Laboratory have created a redox-active interlayer within...
Scientists from Exciton Science have created perovskite solar cells with 21% efficiency,...