New way to manufacture solar cells found

Scientists have found a new, cheaper and easier way to manufacture solar cells, which could challenge the domination of silicon.
The research shows that an alternative material called perovskite is more efficient and adaptable than previously thought, scientists said.
"The challenge to developing efficient and cheap commercially available solar panels has, until now, been dominated by silicon, with emerging alternative solar cells considered minor players," said Lin Leong from Institute of Materials Research and Engineering in Singapore.
"Silicon is very labour-intensive and requires very high temperatures to process. But with alternative cells there is inefficiency in capturing the energy from the Sun," said Leong.

Perovskite is relatively easy to process, and therefore cheaper to manufacture, but also has an efficiency of 22 per cent, close to silicon cells' 25 per cent, researchers said.
The dominance of commercial and research investment in silicon has made it difficult to convince researchers and commercial developers to adopt new technology, they said.

"This new class of solar cell is only around four years old, so although it has high performance, people do not understand the system and why it is doing so well," said Leong.
The research has provided important insights into the basic physics of perovskite solar cells by measuring their efficiency at different temperatures and light intensities.

"Because it had only been tested at room temperatures, people were sceptical about whether it would still work at the higher temperatures under direct sunlight on a rooftop, where it can go up to 60 degrees Celsius," said Leong.
For most conventional or silicon-based solar cell technologies, efficiency worsens as temperature rises.
The study showed the perovskite cells still worked at higher temperatures, with performance peaking at around 57 degrees Celsius - and then declining slightly after that, meaning their performance will be high even on a relatively hot rooftop, researchers said.
It also showed that, contrary to arguments made by some critics, the material was highly efficient at collecting charge through electrodes, they said.

According to Leong, perovskite will eventually challenge silicon commercially.
"In terms of efficiency, perovskite is already close and it can be made much more cheaply," she said.
The findings were published in the journal Advanced Materials.