Introducing Color Centers to Silicon Carbide Nanocrystals for In Vivo Biomarker Applications: A First Principles Study

2013 ◽  
Vol 740-742 ◽  
pp. 641-644
Author(s):  
Bálint Somogyi ◽  
Viktor Zólyomi ◽  
Adam Gali
Keyword(s):  
Silicon Carbide ◽  
First Principles ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Near Infrared ◽  
Living Cells ◽  
Time Dependent ◽  
Color Centers ◽  
Dependent Density

Molecule-sized fluorescent emitters are much sought-after to probe biomolecules in living cells. We demonstrate here by time-dependent density functional calculations that the experimentally achievable 1-2 nm sized silicon carbide nanocrystals can emit light in the nearinfrared region after introducing appropriate color centers in them. These near-infrared luminescent silicon carbide nanocrystals may act as ideal fluorophores for in vivo bioimaging.

Time-Dependent Density Functional Calculations on Hydrogenated Silicon Carbide Nanocrystals

2011 ◽  
Vol 679-680 ◽  
pp. 516-519 ◽  
Author(s):  
Marton Vörös ◽  
Peter Deák ◽  
Thomas Frauenheim ◽  
Adam Gali
Keyword(s):  
Silicon Carbide ◽  
Absorption Spectrum ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Time Dependent ◽  
First Principles Calculations ◽  
Hydrogenated Silicon ◽  
Reconstructed Surface ◽  
Dependent Density

The electronic structure and absorption spectrum of hydrogenated silicon carbide nanocrystals (SiC NC) have been determined by first principles calculations. We show that the reconstructed surface can significantly change not just the onset of absorption but the shape of the spectrum at higher energies. We compare our results with two recent experiments on ultrasmall SiC NCs.

Influence of Oxygen on the Absorption of Silicon Carbide Nanoparticles

2011 ◽  
Vol 679-680 ◽  
pp. 520-523 ◽  
Author(s):  
Marton Vörös ◽  
Peter Deák ◽  
Thomas Frauenheim ◽  
Adam Gali
Keyword(s):  
Silicon Carbide ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Time Dependent ◽  
Optical Gap ◽  
Silicon Carbide Nanoparticles ◽  
Dependent Density

We have investigated the absorption of 0.9, 1.4 nm silicon carbide nanoparticles (SiC NPs) by time-dependent density functional calculations, focusing on the effect of different oxygen adsorbates of the surface. We have found that negatively charged Si-O−, Si-COO− defects dramatically lower the optical gap of SiC NPs. Our findings can help interpret recent controversary experiments on colloidal SiC NPs.

Sign in / Sign up

Export Citation Format

Share Document