High color rendering index white LED successfully developed

An international joint research team recently demonstrated the world's first white LEDs to achieve high color rendering index.

Traditional LEDs can only emit one wavelength per wave. Therefore, the only way to obtain white light from an LED is to put the red, green, and blue LEDs together, letting the yellow light enter the blue LED lens or convert it into a new material such as zinc selenide, while emitting blue light from its active area. The bottom layer glows yellow. These methods can emit white light and are therefore suitable for general illumination, but the Color Rendering Index (CRI) test found that these methods are not suitable for professionals who need to be able to reproduce all colors in the visible spectrum.

Today, Professor Elisabeth Holder of the University of Wuppertal in Germany and his colleagues, together with Professor Hilmi Volkan Demir of the University of Ankara Bilkent in Turkey, have developed a new scheme to produce white LEDs that they can provide with a very high color rendering index, making them suitable for artists. Professional users such as horticulturists.

According to the researchers, the key to this new technology is to embed the inorganic luminescent nanoparticles into a highly fluorescent organic polymeric substrate, which is then extracted as a near-ultraviolet LED to form a hybrid organic/inorganic LED that produces white light. This white light includes almost all wavelengths, so it can accurately display almost any color.

The research team's focus is on combining organic and inorganic materials. By using a layer-by-layer approach, researchers can embed fluorescent yellow, green, and red nanoparticles (in cadmium-selenium with galvanized silicon) into a fluorescent blue organic matrix, and thus adjust the mixture to achieve more than 80 colors. The index is shown (daylight is 100, incandescent light is 90, fluorescence-based LEDs and 65 nanometers are fluorescent tubes. After further optimization, these researchers are expected to increase CRI to 100).