CdSe/ZnS Core-Shell System Enhance the Efficiency of the White Light Generation

Abstract

The synthesis techniques of highly luminescent CdSe/ZnS core-shell composite nanocrystals are reported. The color-conversion, incorporating the photoluminescence emission of CdSe/ZnS core-shell nanocrystals in blue λ=350 nm and green λ=520 nm on near UV-InGaN/GaN LED λ=365 nm, was studied. The generated white light resulting from color-mixing of the emitted wavelengths of  the core-shell composite and that of the near UV emission from the LED was analyzed depending upon the chromaticity coordinates. The X-ray diffraction pattern was used to study the CdSe/ZnS core-shell structure and the nanocrystal size formation. The absorption and photoluminescence spectra of the composite core-shell were investigated. The Gaussian fit was applied to the fluorescence spectrum of the CdSe/ZnS core-shell in order to determine the chromaticity coordinates of the output white light emitted on the chromaticity diagram.