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...

Molecular mechanisms and precursor conversion pathways associated with the reactions that generate colloidal nanocrystals are crucial for the development of rational synthetic protocols. In this study, Fourier transform infrared spectroscopy technique was employed to explore the molecular mechanism associated with the formation of tin-doped indium oxide (ITO) nanocrystals. We found that the rea...

Nanocrystal assemblies are being explored for a number of optoelectronic applications such as transparent conductors, photovoltaic solar cells, and electrochromic windows. Majority carrier transport is important for these applications, yet it remains relatively poorly understood in films comprised of touching nanocrystals. Specifically, the underlying structural parameters expected to determine...

CdS nanocrystals were synthesized in 1-octadecene (ODE) solution with oleic acid (OA) as a capping agent. Freshly prepared CdS nanocrystals showed a weak orangelike fluorescence due to defects on the particle surface. After several weeks' storage, the bulk fluorescence of CdS nanocrystals was dramatically enhanced, which gave the nanocrystals a blue or violet appearance. UV and photoluminescenc...

Metal nanocrystals offer new concepts for the design of nanodevices with a range of potential applications. Currently the formation of metal nanocrystals cannot be controlled at the level of individual atoms. Here we describe a new general method for the fabrication of multi-heteroatom-doped graphitic matrices decorated with very small, ångström-sized, three-dimensional (3D)-metal crystals of d...