Graphene quantum dots (GQDs) have the potential to be applied towards next generation electronics and energy applications. Graphene itself does not possess band gap energy and its usage is limited. However, when their size becomes as small as quantum dots, they exhibit photoluminescence in the ultraviolet, visible, and near infrared ranges. The size of graphene quantum dots ranges approximately 1-4 nm. Due to their quantum confinement effect, GQDs can be applied to photovoltaic devices such as solar cells, bio imaging (cancer cell imaging, protein analysis, cell tracking), various type of sensors, etc.