Renormalization of the band gap in 2D materials near an interface between two dielectrics

Abstract: We investigate how the renormalization of the band gap in a planar 2D material is affected by the consideration of two nondispersive semi-infinite dielectrics, with dielectric constants $\epsilon_1$ and $\epsilon_2$, separated by a planar interface. Using the pseudo quantum electrodynamics to model the Coulomb interaction between electrons, we show how the renormalization of the band gap depends on $\epsilon_1$ and $\epsilon_2$, and also of the distance between the 2D material and the interface between the two dielectrics. In the appropriate limits, our results reproduce those found in the literature for the band gap renormalization when a single dielectric medium is considered.