Multicolor emission tuning of ZnS@SiO2-Eu3+ composite as potential application in light-emitting devices

In this report, we present luminescent properties of a composite based on zinc sulfide quantum dots (ZnS QDs) in a SiO2 matrix, doped with different concentrations of Eu3+ ions and with different thermal treatments in order to obtain white light and a tunable emitting phosphor. Various complementary techniques have extensively studied the evolution of effects of thermal treatment and Eu3+ doping on the crystallinity and emission properties. Transmission electron microscopy certifies the formation of undoped ZnS powder of particles with sizes of approximately 4.6 nm, combined with XRD, shows the amorphous nature of the matrix host as well as the presence of embedded crystalline nanoparticles. The incorporation of the Eu3+ dopant does not produce a significant effect in the crystalline structure of the ZnS@SiO2 composite. Raman spectroscopy results indicate that thermal treatment induced to formation cristobalite-low and Zn2SiO4. The photoluminescence measurements indicated that ZnS@SiO2 nanocomposite exhibit an intense and wide blue emission band centered at around 440 nm under 325 nm excitation, which is modified by the temperature, with the enhancement of the intensity, widening of the band emission, as well as maximum shifting. The calculations of the CIE 1931 chromaticity coordinates show the tuning of the tonality of the emission color from blue to cold white light, these results strengthened the possibility that the prepared samples could be applied as an efficient phosphor in the visible range.

Automated summary

This report presents the luminescent properties of a composite material consisting of zinc sulfide quantum dots (ZnS QDs) in a SiO2 matrix. The composite is doped with different concentrations of Eu3+ ions and subjected to various thermal treatments to achieve white light and tunable emitting phosphors. The effects of thermal treatment and Eu3+ doping on crystallinity and emission properties are extensively studied using complementary techniques.