Tight binding calculations for the optical properties of ellipsoidal silicon nanocrystals

2005 ◽  
Vol 2 (9) ◽  
pp. 3435-3439 ◽  
Author(s):  
F. Trani ◽  
G. Cantele ◽  
D. Ninno ◽  
G. Iadonisi
Keyword(s):  
Optical Properties ◽  
Silicon Nanocrystals ◽  
Tight Binding

The Role of Local Fields in the Optical Properties of Silicon Nanocrystals

2006 ◽  
Vol 958 ◽  
Author(s):  
Fabio Trani ◽  
Domenico Ninno ◽  
Giovanni Cantele ◽  
Giuseppe Iadonisi
Keyword(s):  
Optical Properties ◽  
Local Field ◽  
Silicon Nanocrystals ◽  
Tight Binding ◽  
Visible Spectral Range ◽  
Local Fields ◽  
Strong Suppression ◽  
Field Effects ◽  
Dielectric Model

ABSTRACTIn this paper we discuss the role of local fields in the optical properties of silicon nanocrystals. Using a semiempirical tight binding approach, local field effects are included into the linear response theory, going beyond the standard independent particle approximation. The results show that local field effects give an important contribution to the optical properties of silicon nanocrystals, leading to a strong suppression of the absorption in the visible spectral range. This effect is attributed to the classical surface polarization contribution. A comparison between the atomistic tight binding approach and a classical dielectric model shows that the dielectric model gives reasonable results not only for large, but even for small silicon nanocrystals.

Nonlinear optical properties of plasma enhanced chemical vapour deposition grown silicon nanocrystals

2002 ◽  
Vol 722 ◽  
Author(s):  
G. Vijaya Prakash ◽  
M. Cazzanelli ◽  
Z. Gaburro ◽  
L. Pavesi ◽  
F. Iacona ◽  
...  
Keyword(s):  
Optical Properties ◽  
Chemical Vapour Deposition ◽  
Silicon Nanocrystals ◽  
Nonlinear Optical ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Nonlinear Optical Properties ◽  
Nonlinear Susceptibility ◽  
Closed Aperture ◽  
Third Order

AbstractWe present a systematic study on the nonlinear optical properties of silicon nanocrystals (Si-nc) grown by plasma enhanced chemical vapour deposition (PECVD). The sign and magnitude of both real and imaginary parts of third-order nonlinear susceptibility χ(3) of Si-nc are measured by Z-scan method. While the closed aperture Z-scan reveals a sign of positive nonlinearity, the open aperture measurements suggests a nonlinear absorption coefficients. Absolute values of χ(3) are in the order of 10-9 esu and show systematic correlation with the Si-nc size, due to quantum confinement related effects.

SYMMETRY AND ELECTRO-OPTICAL PROPERTIES OF NANOTUBES

2002 ◽  
Vol 01 (03n04) ◽  
pp. 313-325 ◽  
Author(s):  
M. DAMNJANOVIĆ ◽  
I. MILOŠEVIĆ ◽  
T. VUKOVIĆ ◽  
B. NIKOLIĆ ◽  
E. DOBARDŽIĆ
Keyword(s):  
Carbon Nanotubes ◽  
Optical Properties ◽  
Density Functional ◽  
Tight Binding ◽  
Optical Characteristics ◽  
Optical Transitions ◽  
Matrix Elements ◽  
Selection Rules ◽  
Single Wall Carbon ◽  
Quantum Numbers

The symmetry of single-wall carbon and inorganic tubes is reviewed. For the carbon nanotubes it is used to get the full set of quantum numbers, in the efficient precision (combined density functional and tight-binding methods) calculation of electronic bands and their complete assignation, to obtain the selection rules for optical transitions and the momenta matrix elements for the Bloch eigen-states. The optical characteristics are thoroughly found, and discussed.

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