Encapsulation-Enabled Perovskite–PMMA Films Combining a Micro-LED for High-Speed White-Light Communication
Zhaoming Wang, Zixian Wei, Yuting Cai, Lei Wang, Mutong Li, Ping Liu, Rong‐Jun Xie, Lai Wang, Guodan Wei, H. Y. Fu
Abstract
Cesium lead halide perovskite nanocrystals have recently become emerging materials for color conversion in visible light communication (VLC) and solid-state lighting (SSL), due to their fast response and desirable optical properties. Herein, perovskite nanocrystal-polymethyl methacrylate (PNC-PMMA) films with red and yellow emission are prepared. The PNC-PMMA films, with optical properties such as a short lifetime and air stability, are used to make broadband color converters based on a high-bandwidth 75 μm blue micro-LED (μLED) for VLC. The yellow-emitting CsPb(Br/I)3 PNC-PMMA has a high bandwidth of 347 MHz, while the red-emitting CsPbI3 PNC-PMMA exhibits a higher modulation bandwidth of 822 MHz, which is ∼65 times larger than that of conventional phosphors. After fixing the two PNC-PMMA films in front of the μLED, a qualified warm white light is generated with a correlated color temperature of 5670 K, a color rendering index of 75.7, and a de L’Eclairage (CIE) coordinate at (0.33, 0.35). Although the color conversion of the blue light sacrifices some received power and slightly reduces the overall bandwidth from 1.130 to 1.005 GHz, a maximum real-time data rate of 1.7 Gbps is still achievable using the non-return-to-zero on–off keying modulation scheme, which is ∼6 times higher than that of the previous record. This study provides a practical approach to develop a considerably high-bandwidth white-light system for both high-speed VLC and high-quality SSL.