Preparation And Photoelectronic Properties Of Q-CdS And Its Polymer Nanohybrid Films

Nanocomposite material is an important advancing front in the field of material. The semiconductor nanoparticle/polymer composite films has recently attracted much attention because of their excellent optic-electronic properties. In this paper, the studies on the synthesis, ways of characterization, properties and application of polymic matrix nanocomposite have been reviewed in detail. A series of Q-CdS nanoparticles and its polymer composite films with small size and narrow distribution were prepared. Their quantum size effect was studied. The details are as follows:1. Polymer dispersion method, a new approach to obtain Q-CdS nanoparticles has been presented. A series of monodisperse Q-CdS with different sizes were constructed by using water soluable polymer (PVA, PVP, PAA) as dispersion agents and mercaptan (dodecyl mercaptan, mercapoethanol, thiourea) as surface modifier in polymer networks, and changing the type and amount of polymer and mercaptan, etc. Finally, water soluable Q-CdS powder with better stabilization was obtained through centrifugal precipitation, washing and vacuum dryness.2. Their quantum size effect was studied by UV-Vis spectra, X-ray diffraction and fluorescent spectra. TEM was used to observe the particle size and shape. The result shows that UV-Vis spectra and fluorescent spectra are blue-shift, peak of XRD patterns are broadening. The result indicated that Q-CdS nanoparticles are of small size, narrow distribution and obvious quantum size effect. The XRD patterns shows the coexistence of cubic and hexagonal phases in the Q-CdS nanoparticles.3. The polyvinyl-alcohol (PVA) was used for matrix, A series ofQ-CdS/PVA hybrid films containing CdS with small size and narrow distribution were constructed via in situ method. The size and distribution were controlled by changing the amount of mercaptan and H2S. The interaction between polymer function group and Cd ion (CdS) controlled Q-CdS monodispersion. Obtained results indicated : Q-CdS nanoparticles still show obvious quantum size effect in films.4. CdS nanoclusters and functional polymer (Polyphenylacetylenes and Polyaniline) were blended in chloroform. Through ultrasonic dispersion and volatilization solvent, a series of Q-CdS/poIymer films were successfully prepared. Quantum size effect was observed on fluorescent spectra and UV-Vis spectra. The result indicated that there is obvious interaction between functional polymer and CdS nanoclusters, which is stable for Q-CdS/polymer films.