Continuous Band-Gap Reduction on ZnO Submicrorods via Covering with ZnS1−xSex or ZnSe1−xTex Alloy in Core/Sheath Morphology

Submicrosized alloy cables of ZnO/w-ZnS(1-x)Se(x) (0 < x < 1) and ZnO/s-ZnSe(1-x)Te(x) (0.8 < or = x < 1) have been prepared. The lattice parameters of the sheath show linear compositional dependence following Vegard's law. The composition-band gap dependence follows the trend of E(g)(ZnO/w-ZnS(1-x)Se(x))(x) = 3.60 - 1.77x + 0.87x(2) (0.22 < or = x < or = 1), E(g)(ZnO/w-ZnS(1-x)Se(x)) = 3.25 eV (0 < or = x < or = 0.22), and E(g)(ZnO/s-ZnSe(1-x)Te(x))(x) = 2.65 - 1.82x + 1.41x(2) (0 < or = x < or = 1), respectively. The continuous band-gap modulations on ZnO-based heterostructures are associated with the core/sheath morphology and the nature of the sheath alloys.