Indium-doping boosts perovskite solar cell efficiency

Researchers at the Australian National University (ANU) have developed a new method for fabricating perovskite solar cells that could increase efficiency by around 20 per cent.

(Credit: Jack Fox ANU)
(Credit: Jack Fox ANU)

The manufacturing technique involves adding a small amount of indium to a titanium oxide electron transport layer. According to the research, published in the journal Advanced Energy Materials, indium-doping improves both the conductivity of the transport layer and the band alignment at the perovskite interface compared to pure titanium oxide.

“The prospect of adding a few additional processing steps at the end of a silicon cell production line to make perovskite cells is very exciting and could boost solar efficiency from 25 per cent to 30 per cent,” said Dr Tom White from the ANU Research School of Engineering.

Perovskite cells are good at converting visible light into electricity, while conventional silicon cells perform better with infrared light. Hybrid cells that use a combination of both materials have the potential to significantly improve the overall efficiency of solar technology.

“By combining these two cells, the perovskite cell and the silicon cell, we are able to make much better use of the solar energy and achieve higher efficiencies than either cell on its own,” White added.

“We have been able to achieve a record efficiency of 16.6 per cent for a semi-transparent perovskite cell, and 24.5 per cent for a perovskite-silicon tandem, which is one of the highest efficiencies reported for this type of cell.”

While perovskite cells can improve efficiency, they are not yet stable enough to be used on rooftops. But the potential gains from perovskite, as well as the relative ease with which it can be combined with silicon cells, means extensive work is being done to advance the technology. The ANU research is part of a AU$12.2 million “High-efficiency silicon/perovskite solar cells” project led by the University of New South Wales and supported by AU$3.6 million of funding from the Australian Renewable Energy Agency.