Engineering the electronic and optical properties of the zigzag MoS2/WS2 heterostructure nanotubes

The electronic structures and optical properties of zigzag MoS2/WS2 heterostructure nanotubes (NTs) with different component ratio and uniaxial strain have been investigated by using first-principles calculations. The band gap of the zigzag MoS2/WS2 heterostructure NTs remains the direct band gap with different ratio of WS2 and uniaxial strain. while the band gap of which increases obviously with the increase of WS2 when the ratio is more than half. Moreover, the band gap of the zigzag MoS2/WS2 heterostructure NT decreases linearly with the increase of tensile strain, while the band gap of which increases firstly and then decreases with the increase of compressive strain. The dielectric spectra occur blue shift with the increase of component ratio of WS2. The static dielectric constants decrease monotonously with the increase of the ratio of WS2. Interestingly, the dielectric spectra for parallel and perpendicular to the tube axis exhibit opposite shift under the same strain. The static dielectric constants of which also show the different variation tendency under the same strain. These results suggest that the zigzag MoS2/WS2 heterostructure NTs can be promising candidates for optoelectronic applications.