Tunable electronic and optical properties of the MoS2/MoSe2 heterostructure nanotubes

Abstract

The electronic and optical properties of the MoS 2 /MoSe 2 heterostructure nanotubes (NTs) with different ratios are systematically investigated by first principles calculations. It is found that the zigzag and armchair MoS 2 /MoSe 2 heterostructure NTs retain direct and indirect band gap under different MoSe 2 ratios, respectively. It is interesting that the band gap of the armchair NTs decreases firstly and then increases with the increase of MoSe 2 ratios, while the band gap of the zigzag NTs decreases gradually with the increase of MoSe 2 ratios. Moreover, the dielectric function, absorption coefficient , refractive index and reflectivity coefficient of the MoS 2 /MoSe 2 heterostructure NTs exhibit red shift with the increase of MoSe 2 ratios. Especially, the static dielectric constant ε 1 ( 0 ) and static refractive index n ( 0 ) increase monotonously with the increase of MoSe 2 ratios. These results suggest that the MoS 2 /MoSe 2 heterostructure NTs may serve as promising building blocks for optoelectronic nanodevices . • The band structures of MoS 2 /MoSe 2 heterostructure nanotubes can be modulated. • The variation trends of the band gaps are dependent on chirality. • The optical parameters exhibit red shift with the increase of MoSe 2 ratios. • The static dielectric constant and static refractive index change monotonously.