Innovation in lighting is a continuous endeavor, promoted by lighting architects and design engineers seeking ways to make lighting meet demands of brilliance, energy consumption and space constraints. Now a research team in China has built a light source so thin, flexible and natural in tone it could pass for a sheet of sunlight on your wall. An ultra-slim LED is an innovation in lighting that portends a future where illumination is not a bulb or fixture, but a wallpaper surface.

Replicating daylight indoors is challenging when using LED technology as it tends to be more blue than natural light is. The researchers homed in on tiny quantum dots found as semiconductors that help fine-tune emitted LED light to better simulate natural lighting.

The researchers tweaked red, yellow-green and blue quantum dots and engineered a mix of nanoscale emitters that mimic sunlight. They sandwiched these dots between ultrathin conductive layers, stacking the device to a thickness that makes a human hair look bulky. The result is a flexible white-light panel with a color rendering index north of 92—meaning what you see under its glow looks astonishingly real.

The research team found that their prototypes did not require high voltage. They were able to achieve desired brightness between 8V and 11.5V. Eighty percent of the prototypes outperformed the brightness of a standard computer monitor.

This gives rise to many possibilities. These featherweight LEDs could be laminated into ceilings, wrapped around columns, embedded in furniture or integrated into wearables without adding noticeable bulk. The wall of a room may be made to glow like morning light.

And because quantum dots can be tuned like an equalizer, the same technology could be used in many different applications. For example, they could be outfitted to provide light for indoor farms or support therapeutic lighting for mood and health. The team achieved a spectral match with up to 91.7% similarity to natural sunlight across key wavelengths, which puts these devices alongside other artificial light sources. The next challenge for the research team is to be able to scale the technology for larger, broad-scale applications.

As solid-state lighting inches toward invisibility, we may soon trade our lamps and fixtures for paper-thin luminous sheets that show us a different way to see the light of day.