1. Introduction
The great promise of the rapidly expanding family of 2D materials for practical applications has been hindered behind the ineffective interaction of the light with such low-dimensional structures. For applications such as light detection and generation (light emitting diodes (LEDs) [1] and lasers[2]) strong interaction between the 2D-materials and light is key to the design of devices with practical figure of merits including efficiency and power consumption. Integration of 2D-matrials with optical [3] and plasmonic cavities [4] of different kinds has long been pursued to address this drawback.