Researchers at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia have achieved a new bandwidth record for data communication using visible light. They developed a new visible light communication (VLC) device that uses a color converter that combines traditional materials with perovskites, the crystals that are better known for their potential for solar cells. The new color converter has a bandwidth that is 40 times greater than today’s commercial converters. This significant improvement makes VLC a realistic option for meeting growing demands for wireless data transfer without using the crowded radio spectrum.
VLCs use lasers or LEDs that transmit data in binary code by switching on and off faster than the eye can see. They use a color converter—a component that converts blue LED light into the colors that are needed to make white light to transmit data. The challenge is that color converters typically have small bandwidth, which limits the speed of data transmission. Color converters are usually based on phosphors, which are luminescent materials that are also used in LEDs.
The KAIST team discovered that by adding perovskites to phosphors, the properties changed. This technique increased the color converter’s bandwidth from 12 megahertz (MHz) to nearly 500 MHz and enabled the device to transmit data at a speedy 2 Gigabits per second. Their study is described in a paper called “Perovskite Nanocrystals as a Color Converter for Visible Light Communication,” which published in ACS Nano on May 31, 2016.