Study of electronic structure and transport coefficients of GaN-MoS2 heterostructure

Abstract

The electronic structure and transport properties of GaN-MoS2 heterostructure have been theoretically investigated using first principles calculations. Among the various possibilities of stacking MoS2 over GaN monolayers to form heterostructure, we studied the case in which the S atom is directly placed over the Ga atom. This type of stacking is energetically favourable. The GaN-MoS2 heterostructure preserves the direct band gap nature of MoS2 monolayer i.e. it has direct band gap of 0.97 eV. The valence bands and conduction bands adjoining the fermi level are mostly contributed by N and Mo atoms. To study the performance of both n-type and p-type GaN-MoS2 heterostructure in thermoelectric applications, we investigate the transport coefficients on which the ZT parameter depends. We found that p-type heterostructure has high electrical conductivity as compared to n-type heterostructure. Due to which it has a high magnitude of power factor which is one of the deciding factors in the evaluation of ZT parameter.