CdS Nanocrystals in Chelate Polymer Microparticles: Polymer Size Dependence of The Optical Properties

Abstract

Abstract CdS nanocrystals were prepared in micrometer-sized chelate polymer particles by nucleation of Cd2+ ions with an aqueous Na2S solution. Simulation of the absorption spectral band shapes of CdS under an effective mass approximation was conducted on the basis of the size distributions of the crystals in the polymer, which were estimated by the relevant transmission electron micrograph images. The optical properties and the size distributions of CdS were dependent on the diameter of the polymer particle, when the concentration of an added S2− solution was sufficiently high for rapid nucleation. In the case of the reaction of Cd2+ with a diluted S2− solution, contrarily, the formation of CdS was confined in the surface layer of the host polymer particle with layer-by-layer size distributions. Effects of the host polymer particle size and the concentration of the Na2S solution on the size distributions and the optical properties of CdS are discussed in terms of the apparent rate of nucleation of Cd2+ to CdS.