Synthesis and photoluminescence of ZnS:Cu nanoparticles

• Published in: Optical materials 2006-11, Vol.29 (2), p.313-317
• Main Authors: Peng, W.Q., Cong, G.W., Qu, S.C., Wang, Z.G.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Ii-vi semiconductors; Nanoparticles; Optical materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optics; Photoluminescence; Physics; Zinc sulfide
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2005.10.003

The room-temperature photoluminescence (PL) of copper doped zinc sulfide (ZnS:Cu) nanoparticles were investigated. These ZnS:Cu nanoparticles were synthesized by a facile wet chemical method, with the copper concentration varying from 0 to 2 mol%. By Gaussian fitting, the PL spectrum of the undoped ZnS nanoparticles was deconvoluted into two blue luminescence peaks (centered at 411 nm and 455 nm, respectively), which both can be attributed to the recombination of the defect sates of ZnS. But for the doped samples, a third peak at about 500 nm was also identified. This green luminescence originates from the recombination between the shallow donor level (sulfur vacancy) and the t 2 level of Cu 2+. With the increase of the Cu 2+ concentration, the green emission peak is systematically shifted to longer wavelength. In addition, it was found that the overall photoluminescence intensity is decreased at the Cu 2+ concentration of 2%. The concentration quenching of the luminescence may be caused by the formation of CuS compound.