Solvothermal synthesis, characterization and photoluminescence studies of ZnS:Eu nanocrystals

Abstract

Europium doped zinc sulfide nanocrystals (ZnS:Eu) are prepared by solvothermal method. Crystallite size and lattice constant of the prepared samples are calculated from the X-ray diffraction patterns. The as-prepared samples are found to be a mixture of complex chemical groups. Heat treatment of the samples at 300°C resulted in ZnS:Eu state. The crystal structure is not affected by the increase in the concentration of Eu from 1mol% to 5mol%. Fourier Transform Infrared Spectroscopy (FTIR) studies showed that characteristic absorption bands of hydroxyl groups and the acetate bands increased with increase in Eu concentration. The morphological results studied using Scanning Electron Microscopy (SEM) indicate agglomeration of nanoparticles and a marginal increase in the particle size. Photoluminescence (PL) spectra of the samples showed a prominent emission band peaked at ∼400nm besides three weak ones at ∼422, 485 and 530nm. The PL intensity increased with increase in Eu concentration.