Deposition, structure and properties of polyamide-CdSe-CdS composite material using sorption-diffusion method.

Polyamide (PA) incorporated CdSe-CdS films were deposited using sorption-diffusion method. A single precursor - K2SeS2O6 was used as both sulfur and selenium source. In aq. soln., SeS2O2-6 diffused into the polymer where it reacted with Cd2+ ions to form cadmium chalcogenide particles. Crystallinity of the composite material was analyzed via XRD and both CdSe and CdS were detected within the material at all deposition conditions of temp. and SeS2O2-6 - chalcogenization - exposure time. A complex surface speciation was obtained using XPS anal. Formation of the protonated amide species was obsd. in combination with the adsorbed SO2-4 on the surface of the polymer confirming that SeS2O2-6 and its decompn. products hydrolyzed to form cadmium chalcogenides and H2SO4. A significant red shift in UV-vis spectrum was obsd. with the increasing chalcogenization time of PA, whereas Cd2+ soln. temp. had very little effect on the apparent thickness and the optical properties of the composite materials. SEM surface anal. revealed sub-micron particles deposited on top of the PA-CdSe-CdS composite materials in continuous overlapping films, showing a possible dual crystal growth mechanism. [on SciFinder(R)]