Search for: cadmium-selenides
M.Sc. Thesis Sharif University of Technology ; Iraji Zad, Azam ; Dolati, Abolghasem
The interesting properties of metallic and semiconductor nanowires provide many applications in electronic and optoelectronic devices. In this project, we have synthesized Cu and CdSe nanowires using electrodeposition method. To adjust deposition bath conditions and characterize the structure of deposit first we prepared CdSe thin film on ITO substrates. The used solution was contained 0.1 M CdSO4+ 0.1 mM SeO2 in the acidic situation with pH=2.5. The best reduction potential was determined about -0.5 V. The XPS and XRD analyses showed that the ratio of cadmium to selenium in the films was 1:1 and the film’s structure is amorphous. Optical band gap of the cadmium selenide films was obtained...
Colloidal Synthesis of CdSe Nanoparticles and the Influence of Processing Parameters on Growth kinetics, M.Sc. Thesis Sharif University of Technology ; Asgari, Sirous
Over the past two decades, several studies have been investigated on synthesis and properties of semi-conductor quantum dots because of their applications in sensors, LEDs, detectors, solar cells, etc. One of challenging issues in synthesizing these nano-particles is their size distribution. In this study, Cadmium Selenide was synthesized by the method of colloidal synthesis. X-ray diffraction showed that the crystalline nano-particles have wurtzite structure. For obtaining a uniform size distribution, effect of various parameters such as molar ratio of components and reaction temperature on the growth kinetics of these particles, were studied. Results showed that molar ratio of Selenium to...
A Novel Magnetic Molecularly Imprinted Polymers Nanoparticle as Extracting Medium For Micro-Solid Phase Extraction, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib
This thesis cantain two section. In the first section a novel extracting medium based on magnetic molecularly imprinted polymers (MIPs) nanoparticles was synthesized by chemical polymerization for micro-solid phase extraction. In this work, the modified chitosan magnetite nanoparticles (MNP-CS) was synthesized by co-precipitating Fe2+ and Fe3+ in the chitosan solution [1,2]. The characteristic properties of Fe3O4@MIPs nanoparticles were determined using Fourier transform infrared spectrometer. Extraction efficiency of the novel extracting medium was compared with MNP-CS sorbents for the determination of RhB in aqueous samples, via quantification by spectrofluorimetry. The obtained results...
Morphological manipulation of solvothermal prepared CdSe nanostructures by controlling the growth rate of nanocrystals as a kinetic parameter, Article Journal of Electronic Materials ; Volume 41, Issue 11 , 2012 , Pages 3050-3055 ; 03615235 (ISSN) ; Mohammadi, M. R ; Fray, D. J ; Sharif University of Technology
The morphological manipulation, structural characterization, and optical properties of different cadmium selenide (CdSe) nanostructures are reported. Two different CdSe nanostructures, i.e., nanorods and nanoparticles, were grown by controlling the concentration of precursors (i.e., cadmium nitrate and selenium dioxide) in ethanolamine solvent. By manipulating the kinetic parameter of the process (i.e., growth rate) under constant growth driving force (i.e., degree of supersaturation), the morphology of CdSe nanostructures can be tailored from nanorods to nanoparticles. The optical properties of CdSe nanostructures were investigated using ultraviolet-visible (UV-vis) spectroscopy. The...
Article Journal of Nanostructured Polymers and Nanocomposites ; Volume 7, Issue 1 , 2011 , Pages 18-31 ; 17904439 (ISSN) ; Sadeghi, E ; Hosseinkhani, H ; Mahmoudi, M ; Kalantari, M ; Adeli, M ; Sharif University of Technology
Molecular self-assembly of cadmium selenide quantum dots-end-capped polyrotaxane hybrid nanostructures (PRCdSe QDs) was led to a new type of core-shell hybrid nanomaterials consisting of cadmium selenide quantum dot (CdSe QDs) core and polyrotaxane shell (PR@QDs). Structure of PR@QDs was characterized using various techniques. It has been observed that the size of PR@QDs was between 20-25 nm in which diameter of core and thickness of shell were between 15-20 and 2-3 nm, respectively. Short-term in vitro cytotoxicity tests, using MTT (3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, were conducted on mouse tissue connective fibroblast adhesive cell line (L929) in order to...