Colloidal semiconductor nanocrystals in the range 1-10 nm are promising building blocks for future nanodevices since they show strong quantum confinement effects even at room temperature [1,2]. Colloidal semiconductor nanocrystals consist of an inorganic core, having the same crystal structure as the corresponding bulk semiconductor, surrounded by a shell of capping molecules. These cappping mo...

Silicon nanocrystals embedded in SiO2 were isolated with a selective etching procedure, and the isolated nanocrystals’ excitonic emission energy was studied during controlled oxidation. Nanocrystals having initial diameters, d0, of ,2.9–3.4 nm showed a photoluminescence sPLd blueshift upon oxidatively induced size reduction, as expected from models of quantum confinement. Oxidation of smaller S...

Stable water soluble surfactant coated CdSe nanocrystals with trioctylphosphine (TOP) were obtained by a process of dynamic surface coating with cationic, anionic, and non-ionic surfactants. The surfactant-coated CdSe/TOP nanocrystals were characterized by complementary techniques of UV-VIS and photo-luminescence spectrophotometry, as well as by means of a capillary zone electrophoretic techniq...

Practical, efficient synthesis of metal oxide nanocrystals with good crystallinity and high specific surface area by a modified polymer-network gel method is demonstrated, taking ZnO nanocrystals as an example. A novel stepwise heat treatment yields significant improvement in crystal quality. Such nanophase materials can effectively degrade common organic dyes under solar radiation and can perf...

We derive within the dielectric-continuum model an integral equation that defines interface and confined polar optical-phonon modes in nanocrystals with a wurtzite crystal structure. It is demonstrated theoretically that, while the frequency of confined polar optical phonons in zinc-blende nanocrystals is equal to that of the bulk crystal phonons, the confined polar optical phonons in wurtzite ...

Luminescent graphene quantum dots (GQDs) are encapsulated and stabilized in Zeolitic Imidazolate Framework (ZIF-8) nanocrystals. The GQDs are well confined due to the adsorption on the growing face of the ZIF-8 nanocrystals and have a profound effect on the shape of the nanocrystals from rhombic dodecahedron to spherical. Stabilizing GQDs inside the ZIF-8 nanocrystals results in tailoring of th...

The creation and study of non-metallic nanomaterials that exhibit localized surface plasmon resonance (LSPR) interactions with light is a rapidly growing field of research. These doped nanocrystals, mainly self-doped semiconductor nanocrystals (NCs) and extrinsically-doped metal oxide NCs, have extremely high concentrations of free charge carriers, which allows them to exhibit LSPR at near infr...

The pure and PVA capped ZnS nanocrystals were synthesized by hydrothermal method using zinc nitrate and thioacetamide as the zinc source and sulphur source respectively. The XRD patterns confirmed the formation of cubic phase ZnS nanoparticles with particle sizes 32.6nm and 30.6nm respectively for the pure and PVA capped nanocrystals. The SEM micrographs show the improvement in the particle siz...

Cellulose nanocrystals obtained from natural sources are of great interest for many applications. In water, cellulose nanocrystals form a liquid crystalline phase whose hierarchical structure is retained in solid films after drying. Although tactoids, one of the most primitive components of liquid crystals, are thought to have a significant role in the evolution of this phase, they have evaded ...

Olive-shaped SnO2 nanocrystals were synthesized successfully via a facile hydrothermal route, using tin dichloride hydrate, oxalic acid dihydrate and polyvinylpyrrolidone as reaction precursors, and showed great potential in the large-scale preparation of SnO2 nanocrystals. The prepared SnO2 nanocrystals were characterized using XRD, XPS, SEM, TEM and HRTEM, and showed well-defined olive-shaped...