Understanding the electron’s degrees of freedom (DOF) and their interaction with light will enable the development of new devices with enhanced functionality. 2D quantum materials have recently emerged as an interesting playground to explore electron’s quantum DOF. In this talk, we explore electron’s valley DOF emerging in 2D materials. In particular, we focus on methods to control the valley DOF using electric fields and crystal strains. In the second part, we show the generation of quantum light sources in 2D materials and discuss its implications for solid-state quantum technologies.