Structure of CdS/SiO2 nanocomposites: Influence of the precursor and Cd concentr

2019-06-02 10:50:13

The quantum concentration CD CdS

责任者: Esquivias, Luis;Litran, Rocio;Rodriguez-Ortega, Julian;Blanco, Eduardo;Ramirez-del-Solar, Milagrosa;de la Rosa-Fox, Nicolas 单位: Universidad de Cadiz, Puerto Real, Spain 来源出处: Journal of Sol-Gel Science and Technology,1998,11(3):217-227 摘要: The influence of using TMOS or TEOS in the formation of CdS quantum dots in a silica matrix have been studied by X-ray absorption spectroscopy (XAS). The amount of Cd-S bonds have been monitored as a function of the nominal Cd concentration. The relative amount of CdS crystals depends on the precursor. The use of TEOS is not recommended because it gives a poor yield, especially for high Cd concentration. A discussion of the influence of CdS concentration in matrices from TMOS is carried out from structural models created from their pore volume distribution. The mean pore size becomes smaller and the size distribution more uniform when CdS concentration increases but the nanocrystals of low CdS nominal content present a more efficient quantum confinement. 关键词: Nanostructured materials;Semiconductor quantum dots;Semiconducting cadmium compounds;Silica;Sol-gels;Chemical bonds;Composition effects;Molecular structure;Pore size;Absorption;Quantum confinement