One-step structure-directing approach to Ce3+-doped CaS luminescent micro-nanocrystals

Abstract

A one-step surfactant–ligand co-assisted solvothermal technique was proposed for the preparation of CaS-based luminescent materials with ethylenediamine as solvent, and acetylacetone, 1-dodecanethiol and polyvinylpyrrolidone as capping agents. The morphologies of the obtained particles can be adjusted from an octahedron to a hexagonal prism or a cube by changing the solvent volume ratios of ethylenediamine and different capping agent(s), and the mean sizes of the crystals can be changed in a relatively wide range from tens of nanometers to a few micrometers. The growth process and dynamic mechanism were discussed. A series of CaS:xCe³⁺ nanocrystals were prepared and a small red shift of emission positions was observed from green to yellowish-green with increasing Ce³⁺ concentration.