Optical and luminescence characteristics for Cd1-xErxTe quantum dots prepared via furan-2-ylmethanethiol assisted hydrothermal approach

Abstract

Cd1-xErxTe nanocrystals are synthesized via furan-2-ylmethanethiol assisted hydrothermal approach. The CdTe nanocrystals preserved their cubic structure at all concentrations of Er ions. The Er ions caused an increase of the lattice constant and crystallite size of CdTe QDs. The prepared nanocrystals showed a spherical shape with high monodispersion. The d-spacing was found to be increase due to the increase of Er ions into the CdTe QDs. The EDAX spectra suggested the stoichiometry of the synthesized nanocrystals. The partial replacement of the Er ions in Cd sites gives rise to an improvement of the photoluminescence by more than 4 times and a red shift of their emission peaks was observed. At optimum Er ions concentration, an improvement of their photoluminescence intensity by more than four orders of magnitude and also for quantum yield by 76% are obtained via the increase of the hydrothermal temperature from 50 °C to 250 °C. The increase of the reaction time caused further improvement of photoluminescence intensity by more than 20 times and the quantum yield increased to 91% at reaction time of 3 h. The narrow emission band, high luminescent and the high quantum yield for the Cd0.95Er0.05Te nanocrystals may render them to be employed as efficient material for the manufacturing of light emitting devices.