Organic/inorganic hybrid materials consisting of quantum dots and conjugate polymers are important for the application in light emitting devices. In the present work, we have studied the effect of CdS and CdS/ZnO nanoparticle addition on the structure and fluorescence properties of spin coated PVK (poly(N-vinyl carbozole)) nanocomposite films. CdS nanoparticles were synthesized by simple co-precipitation technique and ZnO shell was grown on the CdS nanoparticles by simple wet chemical approach. The nanoparticles and the hybrid nanocomposites have been characterized by using XRD, SEM, FT-IR, optical absorption and fluorescence spectroscopic techniques. The absorption peak for pure PVK remains at 345.5 nm accompanied with minor hump ~480 nm resulting from the incorporation of nanoparticles. It has been observed that the addition of nanoparticles to the hybrid material results in the enhancement of fluorescence intensity at 410 nm to 450 nm spectral regions. These results are important for the development of new light emitting devices at low fabrication costs.
This work presents a systematic study of the effect of ZnSe nanocrystals (NCs) concentration on the optical and luminescent properties of poly N-vinylcarbazole (PVK) polymer nanocomposites. The ZnSe nanocrystals were synthesized by a simple coprecipitation chemical route, while PVK:ZnSe nanocomposite films were fabricated using the spin coating technique. The samples were characterized by XRD, TEM, SEM, UV-Vis and fluorescence techniques. The X-ray diffraction and TEM studies confirmed the particle size, microstructure and spherical shape of the synthesized nanocrystals. The ZnSe nanocrystals in PVK caused a decrease in optical gap with increasing concentration of nanocrystals. The emission spectra exhibited augmentation in intensity up to 70 wt.% of nanoparticles while further addition resulted in a decrease in luminescence. The structure-property relationships obtained for the present system are important for developing low cost illumination devices.