Scientists at the University of Cambridge studying perovskite materials for next-generation solar cells and flexible LEDs have discovered that they can be more efficient when their chemical compositions are less ordered, vastly simplifying production processes and lowering cost.
‘Messy’ production of perovskite material increases solar cell efficiency
The surprising findings, published in Nature Photonics, are the result of a collaborative project, led by Dr Felix Deschler and Dr Sam Stranks.
The most commonly used material for producing solar panels is crystalline silicon, but to achieve efficient energy conversion requires an expensive and time-consuming production process. The silicon material needs to have a highly ordered wafer structure and is very sensitive to any impurities, such as dust, so has to be made in a cleanroom.
In the last decade, perovskite materials have emerged as promising alternatives.
The lead salts used to make them are much more abundant and cheaper to produce than crystalline silicon, and they can be prepared in a liquid ink that is simply printed to produce a film of the material.
The components used to make the perovskite can be changed to give the materials different colours and structural properties, for example, making the films emit different colours or collect sunlight more efficiently.
You only need a very thin film of this perovskite material – around one thousand times thinner than a human hair – to achieve similar efficiencies to the silicon wafers currently used, opening up the possibility of incorporating them into windows or flexible, ultra-lightweight smartphone screens.
“This is the new class of semiconductors that could actually revolutionise all these technologies,” said Sascha Feldmann, a PhD student at Cambridge’s Cavendish Laboratory.
“These materials show very efficient emission when you excite them with energy sources like light or apply a voltage to run an LED.
“This is really useful but it remained unclear why these materials that we process in our labs so much more crudely than these clean-room, high-purity silicon wafers, are performing so well.”
Image: Artist's impression of perovskite structures
Credit: Ella Maru Studio
Reproduced courtesy of the University of Cambridge
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