Demonstration of Graphene/GaN-Based Micro-LEDs Arrays for Visible Light Communication

With the rapid growth of mobile communication data in recent years, visible light communication (VLC) technology based on GaN LEDs can cope with spectrum crises. However, as a light source device, the modulation bandwidth (MB) and light output power (LOP) are not ideal, which hinders communication quality and system reliability. This work proposes the high-reliability graphene (Gr)/GaN-based micro-light-emitting diodes (micro-LEDs) arrays with an LOP of 46 mW and a high <tex-math notation="LaTeX">$-$</tex-math> 3-dB MB of 610 MHz at the current density of 6.7 kA/cm <tex-math notation="LaTeX">²</tex-math> . The various layers of Gr were adopted to increase carrier radiative recombination rate and current spreading in the quantum wells, which can effectively increase the reliability and LOP, as well as reduce the aging of LOP. With the appropriate layers of Gr, hole injection was enhanced and current expansion was improved accordingly, increasing the MB of the micro-LEDs. Possessing high MB, the micro-LEDs arrays also achieved high LOP and low aging rate under high temperature and humidity conditions by introducing the appropriate number of Gr layers, which will be beneficial to improve the lifespan and reliability of the micro-LEDs. The optimistic results in this letter possess high potential of providing high LOP and MB light sources in VLC system.