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.

Effect of Polymer Capping on Photonic Multi-Core–Shell Quantum Dots CdSe/CdS/ZnS: Impact of Sunlight and Antibacterial Activity

“…Sharp absorption features of PVA-capped CdSe/CdS/ZnS quantum dots with blue shift were indicative of its narrow size distribution. The absorption spectra showed that all the samples were highly absorbent in the UV region 302–380 nm and then showed complete transparency beyond this wavelength . The UV–vis spectra in Figure showed that absorption intensities were enhanced when CdSe core was added with binary and ternary layer showed their improved absorption quality.…”

“…The absorption spectra showed that all the samples were highly absorbent in the UV region 302−380 nm and then showed complete transparency beyond this wavelength. 19 The UV−vis spectra in Figure 2 showed that absorption intensities were enhanced when CdSe core was added with binary and ternary layer showed their improved absorption quality. However, less significant absorption was observed in PVA quantum dots but, PAA was highly absorbing in UV region having least band gap 2.81 nm.…”

Aqueous-phase synthesized CdTe quantum dots: an insight into nanoparticle architecture-quantum yield relationship, characterization, and computational study of small clusters

“…7a shows the peak positions are shifted toward higher angles, this shift is related to the tendency of the atoms to occupy positions corresponding to the diffraction peaks of ZnS. [50][51][52] However, both ZnS and the thin CdS layer of induce a shift to higher angles. A pronounced shift indicates the occurrence of ligand decomposition processes on the QD surface.…”

White Light Generation from Electroluminescence Devices Using TPD:PMMA/QDs/Alq₃

“…Highly luminescent II-VI semiconductor nanocrystals or colloidal quantum dots (QDs) are interesting materials because of their applications in optoelectronics, nonlinear optics, and biology [6]. The electronic structure of colloidal QDs, which typically range from 3-12 nm in diameter, is dominated by quantum size effects.…”