Researchers at KAUST University of Saudi Arabia have reportedly developed a nanocrystalline material that rapidly converts blue to white light. Although technologies such as Wi-Fi and Bluetooth are mature, shortening the wavelength of electromagnetic waves used for information transmission still offers several benefits. The so-called visible light communication (VLC) is the use of unmanaged electromagnetic spectrum, which may be more energy efficient. VLC also offers a way to combine messaging, lighting and display technologies, such as the use of ceiling lights to provide laptops with Internet connectivity. Many such VLC applications require white LEDs, typically by combining diodes that emit blue light with phosphors that convert light into red and green light. However, this conversion process is not fast enough to match the switching speed of LEDs on and off. "The VLC rate achieved with white light produced in this way is limited to 100 million bits per second," said Boon Ooi, professor of electrical engineering at KAUST. Ooi, a member of the KAUST Photonics Laboratory at Abdullah University, and Osman Bakr, associate professor of the KAUST Functional Nanomaterials Laboratory, and their colleagues use nanocrystal-based converters that enable higher data rates . Based on a simple, cost-effective solution, combined with conventional nitride phosphors, the team created cesium lead bromide nanocrystals about 8 nanometers in size. Under blue laser illumination, the nanocrystals glow green and nitrides red, which combine to create a warm, white light. The researchers used a technique called "femtosecond transient spectroscopy" to characterize the optical properties of the nanocrystalline material. They can prove that the optical process of cesium lead bromide nanocrystals takes roughly seven nanoseconds. This means that they can adjust the light emission frequency to 491 MHz, which can be 40x faster than using phosphors, enabling a data transfer rate of 2 billion bits per second. "The rapid response is due in part to the size of the crystals," Bakr said. "Space constraints make it more likely that electrons and holes recombine and emit photons." Importantly, the quality of white light produced using perovskite nanostructures is comparable to current LED technology. Enhanced Printing Machine,Embossed Hot Stamping,Digital Varnish Printer,Enhanced Type Heat Transfer Machine Shenzhen Textalk Graphic Technology Co.,Ltd , https://www.textalkdigital.com