SINGAPORE - A new type of solar cell material called perovskite has been making waves worldwide for its low cost and high efficiency.
Researchers from Nanyang Technological University (NTU) have worked out exactly why the compound is so good at harnessing the sun's energy. They are now trying to make the solar cells even more efficient, which could lead to solar panels becoming up to five times cheaper.
By shooting high-speed lasers at the material, NTU assistant professor of physics Sum Tze Chien and his colleagues discovered that perovskite is deposited on its solar cell base in a way that gives it very few imperfections and flaws.
Electrons can flow straight through it, instead of being trapped by flaws in the material.
"This will allow us to make thicker solar cells which absorb more light and, in turn, generate more electricity," Professor Sum said. The team's work was published last week in the journal Science.
The cost of silicon solar panels has dropped sharply in recent years to US$0.70 (S$0.87) per watt. Most of the cost of a solar panel system goes towards the labour, cables and other equipment.
Perovskite solar cells could be cheaper than conventional silicon ones because they can be made at far lower temperatures and in fewer steps. Silicon solar cells require temperatures of 1,000 deg C.
Currently, perovskite solar cells can convert up to 15 per cent of the sun's energy that falls on them into electricity, close to the efficiency of commercial solar cells. The material can also be attached to plastic for use in consumer electronics, or on steel to use for roofing, said Professor Subodh Mhaisalkar, executive director of the Energy Research Institute at NTU, who contributed to the research.