Effects of Cd concentration on structure and optical properties of the ternary Zn1−xCdxO nanopowder prepared by sol–gel method

•The Zn1−xCdxO nanopowder with different Cd contents is synthesized by sol–gel method.•The effects of Cd content on the structural and optical properties were investigated.•The chemical states of Zn, Cd and O is identified by XPS analysis.•The NBE emission was red-shift from 389 to 406 nm due to the modulation of band gap.

Zn1−xCdxO nanocrystalline powder with different Cd contents (0≤x≤1) has been prepared by new facile sol–gel route. The crystal structure and optical properties were investigated by X-ray diffraction patterns, Transmission electron microscope, X-ray photoelectron spectroscopy, Photoluminescence. As x varied from x=0 to 0.25, the Zn1−xCdxO nanopowder exhibits a hexagonal wurtzite structure of pure ZnO without any significant formation of a separated CdO phase. For the samples with 0.5≤x≤0.85, the Zn1−xCdxO nanopowder exhibits the coexistence of hexagonal ZnO and cubic CdO phase, meanwhile, the content of ZnO phase decreases while that of CdO increases with increasing the Cd content x. The ultra-violet near-band-edge emission of the Zn1−xCdxO nanopowder was monotonously red-shifted from 389 nm (x=0) to 406 nm (x=0.25) due to the direct modulation of band gap caused by Cd substitution.

Graphical abstractThe UV NBE emission from Zn1−xCdxO (0 ≤x≤ 0.25) is monotonously red-shifted from ~389 to ~406 nm due to the shrinkage of band gap caused by Cd substitution.Figure optionsDownload full-size imageDownload as PowerPoint slide