High-Performance Metric of Graphene-Based Heterojunction LEDs and PDs in Visible Light Communication Systems

Abstract

Due to the considerable attention in GaN-based semiconductor materials such as large-size, low-cost amorphous SiO2 substrate, high-frequency, and efficient energy design with a low level of light sources, there are more applications in optoelectronics components, such as light-emitting diodes (LEDs), laser diodes (LDs), and indium gallium nitride (InGaN)-based photodetectors (PDs). The high bandwidth of LED transmitters and the high signal-to-noise ratio (SNR) of PDs receivers have great advantages in visible light communication (VLC) systems. Nevertheless, the low data rate speed influences the application of GaN-based LEDs and InGaN-based PDs which have a traditional structure in VLC systems. Given its excellent physical and chemical characteristics, graphene is an attractive material for LEDs and PDs technologies. Combining graphene (Gr) with other materials such as InGaN or GaN can further eliminate the shortcomings of graphene and lead to high-performance Gr/InGaN-based LEDs and Gr/GaN-based PD heterojunctions. It finds that the application of metal nanorods with graphene gap layers by metal-organic chemical vapor deposition (MOCVD) as monolayer Gr (M-Gr) or three-layer Gr (T-Gr) can make a perfect optoelectrical property. The T-Gr/GaN LEDs and T-Gr/InGaN PDs exhibit high responsivity. Furthermore, nanophotonics is a significant field in which a VLC modulator provides various optical device applications employing single-photon devices, quantum communications, advanced plasmonics, and electro-optic modulator architectures. This is due to the use of high-quality GaN or InGaN growth layers and the limited density of T-Gr states. The T-Gr/GaN LEDs and T-Gr/InGaN PDs have a rapid response time and an excellent responsivity, respectively, and high-speed modulation capability (i.e., electro-optic modulator structures) with considerable potential for selective sensing of the VLC system in 6G networks.