{Reference Type}: Journal Article {Title}: A Review on Graphene-Based Light Emitting Functional Devices. {Author}: Junaid M;Md Khir MH;Witjaksono G;Ullah Z;Tansu N;Saheed MSM;Kumar P;Hing Wah L;Magsi SA;Siddiqui MA; {Journal}: Molecules {Volume}: 25 {Issue}: 18 {Year}: Sep 2020 14 {Factor}: 4.927 {DOI}: 10.3390/molecules25184217 {Abstract}: In recent years, the field of nanophotonics has progressively developed. However, constant demand for the development of new light source still exists at the nanometric scale. Light emissions from graphene-based active materials can provide a leading platform for the development of two dimensional (2-D), flexible, thin, and robust light-emitting sources. The exceptional structure of Dirac's electrons in graphene, massless fermions, and the linear dispersion relationship with ultra-wideband plasmon and tunable surface polarities allows numerous applications in optoelectronics and plasmonics. In this article, we present a comprehensive review of recent developments in graphene-based light-emitting devices. Light emissions from graphene-based devices have been evaluated with different aspects, such as thermal emission, electroluminescence, and plasmons assisted emission. Theoretical investigations, along with experimental demonstration in the development of graphene-based light-emitting devices, have also been reviewed and discussed. Moreover, the graphene-based light-emitting devices are also addressed from the perspective of future applications, such as optical modulators, optical interconnects, and optical sensing. Finally, this review provides a comprehensive discussion on current technological issues and challenges related to the potential applications of emerging graphene-based light-emitting devices.