Enhanced Modulation Bandwidth by Integrating 2-D Semiconductor and Quantum Dots for Visible Light Communication

Abstract

Light-emitting devices present a tremendous potential for visible light communication (VLC) due to their dual functionality as both communication and lighting devices. Herein this study, the significant enhancement in VLC modulation bandwidth by integrating two-dimensional (2D) semiconductor and quantum dots (QDs) emitter is reported. Generally, the modulation bandwidth of CdSe-based QDs is limited to only less than 25 MHz; however, with the proposed hybrid emitter, a maximum modulation bandwidth of 130 MHz for CdSe/ZnS QDs emitter is able to be achieved. The WSe2 monolayer is integrated into an Au–nanorod–decorated CdSe/ZnS QDs emitter to achieve high modulation performance. The modulation bandwidth of the hybrid QD–Au–WSe2 emitter (130 MHz) is found to be higher than those of the pristine QDs and QD–WSe2 heterostructure without Au nanorods (79 and 91 MHz, respectively). A significant increase is observed in the transition rate of QDs excitons when they are integrated with Au nanorods and WSe2 monolayer, which is substantiated by a reduction in average carrier lifetime from time-resolved photoluminescence analysis. This approach and the findings open an opportunity to apply 2D semiconductors into the next-generation miniature VLC devices, for high-speed optical communications.