Enhancement of CdSe quantum dots luminescence by calcium ions

Water soluble functionalized CdSe quantum dots (QDs) have been prepared via water based route technique by using safe and low cost materials at low temperature 75 °C. The XRD measurements of the functionalized CdSe quantum dots showed that these quantum dots have a cubic phase with zinc blend structure. The TEM measurements depicted that these quantum dots are mono-dispersed with spherical shape size about 4 nm. The HRTEM measurements confirmed that the prepared quantum dots have single crystalline cubic structure with lattice parameter 0.61 nm. The EDX measurements indicated that the prepared quantum dots are highly pure and there are no impurities in the structures. The influence of calcium metal ions on the FL intensity of the functionalized CdSe QDs was enhanced the FL intensity by 5-times at concentration 0.8 μM. The enhancement effect of Ca2+ ion on the fluorescence emission of CdSe QDs is found to be concentration dependence.