The luminescence characteristics of multicolors-tunable Zn1-xErxSe QDs prepared via microwave irradiation technique for light emitting diode applications

Abstract

The inclusion of rare earth element in the semiconducting IIVI nanocrystals has shown auspicious color-tunable quantum dots because it acts as luminescent centers due to its plentiful emission colors that came from the 4f and 5d electronic transition. Here we report about creation of Zn1-xErxSe QDs at diverse erbium dopant concentrations, for the first time, to get color-tunable QDs with outstanding luminescence emission intensity. The structure, morphology and optical absorption/emission characteristics were emphasized for this new family of quantum dots. The introducing of Er-dopant in the ZnSe crystal lattice caused an expansion of its lattice constant from 0.54 nm to 0.56 nm. The Er-dopant caused an increasing of ZnSe sizes from 2.4 nm to 6.7 nm. The optical property of Zn1-xErxSe QDs disclosed the ability of the Er-dopant to reduce the optical bandgap of the ZnSe nanocrystals from 3.28 eV to 2.96 eV. The luminescence property revealed that the Er-dopant acted as color centers and emitting highly intense light with diverse wavelengths from 375 nm to 420 nm. The Er-dopant improved the quantum yield of the ZnSe QDs from 23 % to 87 % and decreased the luminescent band width and reduced the Stokes shift. The sharp and highly intense multicolor Zn1-xErxSe QDs made them promising nanostructures for light emitting diode application potential.