Light emission from Si quantum dots

Light Emission from CdS Quantum Dots Stabilized by Sugars

CdS nanoparticles were successfully synthesized using starch, amylopectin and maltodextrin, as a capping agent. Optical properties of the final products have been investigated by photoluminescence spectroscopy and Raman scattering. The atomic force microscopy gave a particle of an average size of approximately 6 nm. Our research reveals that all prepared sugar–quantum dot aqueous solutions were...

Structural origin of light emission in germanium quantum dots

We used a combination of optically-detected x-ray absorption spectroscopy with molecular dynamics simulations to explore the origins of light emission in small (5 nm to 9 nm) Ge nanoparticles. Two sets of nanoparticles were studied, with oxygen and hydrogen terminated surfaces. We show that optically-detected x-ray absorption spectroscopy shows sufficient sensitivity to reveal the different ori...

Realization of lasing emission from graphene quantum dots using titanium dioxide nanoparticles as light scatterers.

The luminescent capability of graphene quantum dots (GQDs) was investigated and compared with that of carbon nanodots (C-dots) obtained from the same functionalization process. It was found that the optical gain of GQDs is higher than that of C-dots due to their geometrical advantages such as larger surface area to volume ratio and smaller volume. Under optical excitation at 266 nm, lasing emis...

Active liquid crystal tuning of metallic nanoantenna enhanced light emission from colloidal quantum dots.

A system comprising an aluminum nanoantenna array on top of a luminescent colloidal quantum dot waveguide and covered by a thermotropic liquid crystal (LC) is introduced. By heating the LC above its critical temperature, we demonstrate that the concomitant refractive index change modifies the hybrid plasmonic-photonic resonances in the system. This enables active control of the spectrum and dir...

Strain relaxation in self-assembled Ge(Si)/Si quantum dots