New mark on solar scale
Australian engineers have smashed the world efficiency record for a new kind of solar cell.
Perovskites are the trendy new materials in solar cell research, as they are flexible, cheap to produce and simple to make.
A team at the University of New South Wales has announced it has achieved the highest efficiency rating with the largest perovskite solar cells to date.
The team achieved a 12.1 per cent efficiency rating for a 16 cm2 perovskite solar cell - the largest single perovskite photovoltaic cell certified with the highest energy conversion efficiency, independently confirmed by the international testing centre Newport Corp, in Bozeman, Montana.
The new cell is at least 10 times bigger than the current certified high-efficiency perovskite solar cells on record.
The team has also achieved an 18 per cent efficiency rating on a 1.2 cm2 single perovskite cell, and an 11.5 per cent for a 16 cm2 four-cell perovskite mini-module, both independently certified by Newport.
“This is a very hot area of research, with many teams competing to advance photovoltaic design,” said UNSW research leader Dr Anita Ho-Baillie.
“Perovskites came out of nowhere in 2009, with an efficiency rating of 3.8 per cent, and have since grown in leaps and bounds. These results place UNSW amongst the best groups in the world producing state-of-the-art high-performance perovskite solar cells... I think we can get to 24 per cent within a year or so.”
Perovskite is a structured compound, where a hybrid organic-inorganic lead or tin halide-based material acts as the light-harvesting active layer.
They are the fastest-advancing solar technology to date, and are attractive because the compound is cheap to produce and simple to manufacture, and can even be sprayed onto surfaces.
“The versatility of solution deposition of perovskite makes it possible to spray-coat, print or paint on solar cells,” said Ho-Baillie.
“The diversity of chemical compositions also allows cells be transparent, or made of different colours. Imagine being able to cover every surface of buildings, devices and cars with solar cells.”
Most of the world’s commercial solar cells are made from a refined, highly purified silicon crystal and, like the most efficient commercial silicon cells, need to be baked above 800˚C in multiple high-temperature steps. Perovskites, on the other hand, are made at low temperatures and 200 times thinner than silicon cells.
But although perovskites hold much promise for cost-effective solar energy, they are currently prone to fluctuating temperatures and moisture, making them last only a few months without protection.
Along with every other team in the world, Ho-Baillie’s is trying to extend its durability.
The announcement was made at the Asia-Pacific Solar Research Conference in Canberra.