Monolayer MoS2 on a substrate of hexagonal boron nitride

In this research we want to see if hexagonal boron nitride is a suitable candidate as a substrate for a monolayer of molybdenum disulfide. For a monolayer of molybdenum disulfide on top of a monolayer of hexagonal boron nitride we calculate two possible optimized structures with a distance between the planes of 4:89 A with a binding energy per molybdenum disulfide unit cell of -2.778 eV and 8.10 A with a binding energy per molybdenum disulfide unit cell of -2.634 eV. We plot the total energy versus the seperation distance en find that the structure with a seperation of 4.89 A is a stable structure and the structure with the seperation of 8.10 A is a metastable structure. We plot the band structure for the metastable structure and find a direct band gap of 1.83 eV at K point. For the band structure of the stable structure we find that the band gap is indirect between H and K. We fifind that this is because of the bands with nitrogen pz character that have moved down due to hybridization to create an indirect band gap. We plot the projected density of states for the boron nitride atoms and the molybdenum disulfide atoms for the stable structure and find a band gap of 1.83 eV. We conclude that hexagonal boron nitride is a suitable candidate as a substrate for a monolayer of molybdenum disulfide. We note that the band gap is indirect for a stable structure of a monolayer of molybdenum disulfide on top of a monolayer of hexagonal boron nitride. We also note that there is a direct band gap for the metastable structure. Further research may be done to find a stable structure with a direct band gap.