Colourful solar panels blend into surroundings more smoothly
Image credit: Dreamstime
Researchers have developed solar panels that can be produced in different colours while being almost as efficient as traditional devices.
Solar panels are typically deep black because it is the most efficient colour at absorbing energy from sunlight.
Most attempts to give the devices colour end up decreasing their ability to absorb light and generate power.
But this colour limitation can mean they are not appropriate to use in many architectural designs. The new breakthrough could see solar panels used in decorative settings where they can blend more smoothly into their surroundings.
Developed by a team of researchers funded by the National Natural Science Foundation of China, the new panels were produced in blue, green and purple hues while only dropping the efficiency of power generation from 22.6 to 21.5 per cent.
Attempts at colourful solar panels have used structural sources of colour that take advantage of microscopic shapes to only reflect a very narrow, selective portion of light, like the scales on butterfly wings.
However, previous technologies designed to incorporate structural colour have given panels an undesirable iridescence or been expensive to implement at a large scale.
The researchers developed a new way of giving solar panels colour using a structural material that is easy and inexpensive to apply while maintaining its ability to produce energy efficiently.
The team sprayed a thin layer of a material called a photonic glass onto the surfaces of solar cells.
The glass was made of a thin, disorderly layer of dielectric microscopic zinc sulfide spheres. Although most light could pass through the photonic glass, selective colours were reflected back based on the sizes of the spheres.
The team also found that solar panels manufactured with this photonic glass layer maintained their colour and performance during standard durability tests, and that the fabrication could be scaled up. The researchers plan to explore ways to make the colours more saturated, as well as methods to achieve a wider range of colours.
In 2020, another team unveiled transparent solar panels with a record-breaking efficiency of 8 per cent that could be used to generate renewable energy from buildings.
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