Quantum Dot Displays Are a Thing of the Past: Koreans Create Nanoparticles with a Full Spectrum of Pure Colors

Researchers at the Korea Institute of Science and Technology (KIST) have reported the development of a technology for producing nanoparticles with a full spectrum of radiation for color displays with ultra-high color rendering. Today, such problems are solved by color displays with so-called quantum dots. South Korean scientists have gone further and created the basis for creating virtually solid structures that emit pure colors, which will bring the color rendering of displays closer to the ideal.

Image source: KIST

Each nanoparticle is a nanostructure with a core and several shells — a multilayer system in which several layers of shells surround a central core particle. This allows for high-purity RGB light to be produced from a single nanoparticle by adjusting the infrared excitation wavelength. A nanoparticle display would not require a triad of subpixels made up of individual RGB components to reproduce the entire color spectrum.

Each nanoparticle will act as a pixel with a full spectrum of luminescence, which also opens up the possibility of achieving incredibly high resolution displays. And this is a direct path to creating real stereoscopic screens and the effect of full immersion in a volumetric image without virtual reality glasses. The developers from KIST consider the creation of 3D screens using full-color nanoparticles to be a more important achievement than the production of conventional displays with improved color rendering.

Current materials are unable to emit three primary colors—red (R), green (G), and blue (B)—simultaneously from a single nanoparticle. At least, they cannot do so at the high intensity required for a bright, saturated image. Scientists at KIST have overcome this limitation by developing a core and multilayer shell of nanoparticles, each layer of which responds differently to exciting infrared light.

In particular, the core of the nanoparticle emits green light, the middle shells emit red light, and the outer shells emit blue light. Excitation occurs using light of different wavelengths in the near infrared range. The nanoparticles developed by the researchers are capable of simultaneously reproducing different colors, providing a wide color gamut: 94.2% of the NTSC color space and 133% of the sRGB color space.

«Direct conversion nanoparticles capable of absorbing light in the near infrared range and reproducing full-color luminescence with high color rendering will allow commercialization of 3D displays on which it will be possible to view real volumetric images. These nanoparticles can be used not only in display technology, but also as a protective material to prevent counterfeiting and unauthorized access,” the developers explained.