New research at King's College London may lead to improved solar cells and LED-displays. Researchers from the Biophysics and Nanotechnology Group at King's, led by Professor Anatoly Zayats in the department of Physics have demonstrated in detail how to separate colours and create 'rainbows' using nanoscale structures on a metal surface. The research is published in Nature's Scientific Reports.
More than 150 years ago, the discovery at King's of how to separate and project different colours, paved the way for modern colour televisions and displays. The major challenge for scientists in this discipline nowadays is the manipulation of colour at the nanoscale. This capability will have important implications for imaging and spectroscopy, sensing of chemical and biological agents and may lead to improved solar cells, flat-screen tv's and displays.
Researchers at King's were able to trap light of different colours at different positions of a nanostructured area, using especially designed nanostructures. Depending on the geometry of the nanostructure, a trapped rainbow could be created on a gold film that has the dimension on the order of a few micrometers - about 100 times smaller than the width of a human hair.
Professor Zayats explained: 'Nanostructures of various kinds are being considered for solar cell applications to boost light absorption efficiency. Our results mean that we do not need to keep solar cells illuminated at a fixed angle without compromising the efficiency of light coupling in a wide range of wavelengths. When used in reverse for screens and displays, this will lead to wider viewing angles for all possible colours.'
The big difference to natural rainbows - where red always appears on the outer side and blue on the inner side - is that in the created nanostructures the researchers were able to control where the rainbow colours would appear by controlling the nanostructures' parameters. On top of this, they discovered that it is possible to separate colours on different sides of the nanostructures.
Co-author Dr Jean-Sebastien Bouillard from King's said: 'The effects demonstrated here will be important to provide 'colour' sensitivity in infrared imaging systems for security and product control. It will also enable the construction of microscale spectrometers for sensing applications.'
The ability to couple light to nanostructures with multicolour characteristics will be of major importance for light capturing devices in a huge range of applications, from light sources, displays, photo detectors and solar cells to sensing and light manipulation in optical circuits for tele- and data communications.
King's College London: http://www.kcl.ac.uk
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Free-living songbirds show increased stress hormone levels when nesting under white street lights. But different light spectra may have different physiological effects as this study finds, suggesting that using street lights with specific colour spectra may mitigate effects of light pollution on wildlife
Scientists identify the condition aphantasia, in which people cannot create images in their head
The dust in our homes contains an average of 9,000 different types of fungi and bacteria, a study suggests.
A mosquito can bear up to 23 times its total body weight on each leg, which is crucial for landing on water – the insect's secret is way it stands
Tropical species with smaller geographical ranges are more likely to die out in a warming climate than those that can adapt by ‘invading’ new regions
Most people think of bacteria as germs, signs of filth, or unwanted bringers of disease. Slowly, that view …
The gloomy octopuses crowded at Jervis Bay, Australia, appear to spit and throw debris such as shell at each other in what could be an intentional use of weapons
Therapies based on hormones that make us more trusting enhance our natural placebo effect – a finding that could alter the way clinical trials are conducted
The blind, hairless babies born recently at Washington D.C.'s National Zoo are completely dependent on their mothers—who can sometimes accidentally crush them.
The poop-hoarding insects have an amazingly advanced internal GPS that allows them to navigate by day or night.