Ultralow-power, ultrahigh-definition displays and screens that will be easier on the eyes could be possible with technology being developed by researchers at the University of Central Florida (UCF). Their approach illuminates the display by reflecting light from the surrounding environment, rather than by using energy-intensive LEDs to light the display from behind the screen.
The approach is bioinspired. Many animals display color by scattering and reflecting light when the light hits the nanoscale structures on their bodies.
“If we see butterflies, octopuses, or many beautiful birds, their color actually originates from nanoscale structures on their feathers, skin, or scales,” professor Debashis Chanda said. “What the butterfly does is simply scatter light back in a way that it creates all this beautiful color without absorbing anything.”
Similar to a butterfly, the technology known as plasmonic color display can show different colors based on the size, shape, and patterns of reflective metallic nanostructures inside a screen. However, the technology has limited ability to display the correct color at different angles and fabricate it over large areas.
To display colors that do not depend on viewing angle, Chanda and his team made nanostructures into precise designs that allowed the researchers to control angle-independent light scattering. The researchers enabled nanoparticles to self-assemble in a quasi-random pattern on a predesigned substrate and optimized the self-assembly process so that a specific color could be created by changing nanoparticle size. Using ultrahigh vacuum physical vapor deposition, they created dense arrays of particles in near-field proximity to a mirror. The gaps between adjacent particles and the mirror led to multidimensional coupling of localized plasmonic modes, resulting in a singular resonance with low angular dispersion and about 98% absorption of incident light at the desired wavelength.