Metamaterials based on mixture of Au and CdZnSe\ZnS nanoparticles for future sensorics

The design development and investigation of multicomponent nanostructured materials are the most promising research areas in modern Materials Science. Such materials combine and enhance the properties of each component, and... [ view full abstract ]

The design development and investigation of multicomponent nanostructured materials are the most promising research areas in modern Materials Science. Such materials combine and enhance the properties of each component, and also possess new properties. Therefore they are called metamaterials. In this paper we developed protocols for the formation of porous metamaterials based on mixtures of Au and CdZnSe\ZnS nanoparticles and investigated their optical properties.

Colloidal Au nanoparticles and semiconductor alloyed quantum dots (QDs) were synthesized by the organo-metallic method in colloidal solution. The developed protocols for the metamaterials formation are based on destabilization of colloidal solutions. (Fig. 1(a)). Hybrid complexes from Au particles and QDs were formed in the solution volume and fell onto the silicon substrate in the vial. Thus, porous structures with a shape varying from a spherical to flower-like were obtained. Figure 1 (b, c) shows SEM images obtained by electron microscopy (Merlin, Zeiss). The shape and size of the structures depend strongly on the method of colloidal solution destabilization.

The optical properties of the obtained metamaterials were studied using a laser scanning confocal microscope (LSM-710, Zeiss). Figure 2 shows a photoluminescent image of a sample containing flower-like superstructure. Spectral analysis showed that luminescent properties are changed as compared with those of structures formed by QDs only and for a QD colloidal solution (dashed lines). This can be explained by the interaction of Au nanoparticles and QDs in the superstructure.

The developed protocols for the formation of porous metamaterials with unique optical properties can be utilized for the development of the active materials for sensorics. The results on optical properties will expand the understanding of the interaction of components in hybrid nanostructured materials.