Scientists from Australia’s Exciton Science have shown how next-gen solar cells could perform better when there’s a camera around.
According to the scientists from Exciton Science’s ARC Centre of Excellence and their collaborators at Monash University, Wuhan University of Technology and CSIRO Energy, a literal ‘trick of the light’ can detect imperfections in next-gen solar cells, boosting their efficiency to match that of existing silicon-based versions.
On small scales, perovskite solar cells are already almost as efficient as silicon ones.
However as the scale increases, the perovskite cells perform less well; this is due to the nanoscale surface imperfections resulting from the way they are made.
The Exciton Science team and their collaborators have now come up with a remedy to resolve this issue – with a camera.
The scientists have described how critical imperfections invisible to the naked eye can be detected by shining blue light onto the cells and recording the infrared light that bounces back.
The technique employs a property of solar cells called ‘photoluminescence’.
This is the process by which an electron inside a molecule or semiconductor is briefly powered-up by an incoming photon.
When the electron returns to its normal state, a photon is spat back out.
Microscale flaws alter the amount of infrared produced. Analysing how the extent of the light emitted from the solar cell varies under different operating conditions gives clues to how well the cell is functioning.
“Using this technique, we can rapidly identify a whole range of imperfections,” says Dr Rietwyk, an Exciton Science researcher based at Monash University.
“We can then figure out if there are enough of them to cause a problem and, if so, adjust the manufacturing process to fix it.”
“It makes for a very effective quality control method.”
Image and content: Exciton Science