Australian researchers say stacking PV cells may make solar ever cheaper and more efficient

A material touted as a candidate for next-generation solar technology is showing more promise, with Australian scientists behind its success.

The next-generation of solar technology could be cheaper, more efficient and a step closer to reality after advances by a team of Australian scientists.

The group, from the University of NSW, published evidence they had improved performance from a promising solar cell material this week and broke international records doing so.

But the achievement, verified by the CSIRO, will need to be followed by additional research before it can be deployed on rooftops or even windows.

The announcement comes after Australia set a record for solar energy generation last year, becoming responsible for more than 12 per cent of the nation’s power, and after more than 4.2 million households installed rooftop solar panels.

The researchers, from UNSW’s School of Photovoltaic and Renewable Energy Engineering, investigated ways to boost the efficiency of a material called antimony chalcogenide that has been tipped for use in future solar technology.

The findings, published in the journal Nature Energy, showed the group was able to boost the power conversion efficiency of the material to 11.02 per cent in a university lab and to a rate of 10.7 per cent as certified by the CSIRO.

The world-leading result could keep antimony chalcogenide in the running as a candidate for more efficient solar technology, UNSW Professor Xiaojing Hao said.

The next generation of solar panels would be designed with tandem cells, she said, in which two or more solar cells were stacked on top of one another.

“What researchers around the world are trying to work out is what material is best to use as the top cell in partnership with a traditional silicon cell,” she said.

“Antimony chalcogenide is one of those and (seems) very positive, especially given its distinct properties.”

The material is abundant and inexpensive to use, is more stable than other candidates, and can be deployed in a layer much thinner than a human hair to improve energy efficiency.

The researchers identified a barrier to its use in the uneven distribution of sulfur and selenium, and Dr Chen Qian said they addressed it by adding sodium sulphide during the manufacturing process.

“It was like driving a car up a steep slope,” he said

“If you do that, you need more fuel to get to the end, whereas if the road is flat it’s more efficient to reach there.”

Further research would involve adding chemical treatments to the material to improve its output, Dr Qian said, and research would continue over the “next few years”.

“We believe an achievable aim is to increase the efficiency up to 12 per cent in the near future by addressing the challenges that still remain, one step at a time,” he said.

Further breakthroughs could be used in the university’s spin-off company, Sydney Solar, which is developing transparent solar stickers that promise to generate energy from windows.

AAP