A Semi-Quantitative Analysis of Far-Infrared Absorption in Dynamically Disordered Gallium Arsenide

2003 ◽  
Vol 17 (13n14) ◽  
pp. 783-787 ◽  
Author(s):  
M. A. Grado-Caffaro ◽  
M. Grado-Caffaro
Keyword(s):  
Experimental Data ◽  
Quantitative Analysis ◽  
Optical Absorption ◽  
Density Of States ◽  
Infrared Absorption ◽  
Mathematical Expression ◽  
Far Infrared ◽  
Structural Disorder ◽  
Infrared Range ◽  
Electronic Density

A mathematical expression for the coefficient of optical absorption in amorphous GaAs referred to the far-infrared range is obtained by neglecting the spectrum contribution corresponding to structural disorder. In addition, our results are compared with experimental data and several aspects related to the electronic density of states are discussed.

A SPECIAL MODEL ON OPTICAL ABSORPTION OF AMORPHOUS GaAs IN THE FAR-INFRARED RANGE

1999 ◽  
Vol 13 (17) ◽  
pp. 611-615 ◽  
Author(s):  
M. A. GRADO-CAFFARO ◽  
M. GRADO-CAFFARO
Keyword(s):  
Experimental Data ◽  
Optical Absorption ◽  
Absorption Coefficient ◽  
Far Infrared ◽  
Structural Disorder ◽  
Optical Absorption Coefficient ◽  
Infrared Range ◽  
Electronic Density ◽  
Special Model ◽  
Theoretical Results

The optical absorption coefficient of amorphous GaAs for the far-infrared range is calculated. Results from this calculation are compared with experimental data and with other theoretical results. In our approach, spectrum contribution corresponding to structural disorder is neglected. Moreover, total electronic density of states is determined.

INFRARED ABSORPTION IN PARTIALLY DISORDERED K2CuCl4·2H2O-TYPE COMPOUNDS

2004 ◽  
Vol 18 (17) ◽  
pp. 909-911 ◽  
Author(s):  
M. A. GRADO-CAFFARO ◽  
M. GRADO-CAFFARO
Keyword(s):  
General Theory ◽  
Optical Absorption ◽  
Density Of States ◽  
Infrared Absorption ◽  
Point Of View ◽  
Infrared Range ◽  
Electronic Density ◽  
Electronic Density Of States ◽  
Approximate Relationship

An approximate relationship for the coefficient of optical absorption valid, in principle, for the infrared range, corresponding to K 2 CuCl 4·2 H 2 O -type compounds is derived from a model for electronic density of states. These compounds are assumed to be partially disordered from the point of view of the general theory of solids.

scholarly journals A Brief Study to Clarify Some Aspects Related to Vibrational Density of States for the Far Infrared Range in Amorphous Semiconductors

1998 ◽  
Vol 20 (3) ◽  
pp. 143-145 ◽  
Author(s):  
M. A. Grado-Caffaro ◽  
M. Grado-Caffaro
Keyword(s):  
Optical Absorption ◽  
Density Of States ◽  
Far Infrared ◽  
Structural Disorder ◽  
Amorphous Semiconductors ◽  
Infrared Range ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Vibrational Density Of States ◽  
Vibrational Density

Phonon density of states of amorphous semiconductors for the far-infrared range is examined analytically. On the basis of this formulation, optical absorption corresponding to structural disorder is evaluated and discussed at the far-infrared range for a-Ge and a-Si.

A MODEL FOR OPTICAL ABSORPTION OF AMORPHOUS GaAs IN THE FAR-INFRARED RANGE BY USING AN OPERATIONAL TECHNIQUE

1999 ◽  
Vol 13 (25) ◽  
pp. 919-923 ◽  
Author(s):  
M. A. GRADO-CAFFARO ◽  
M. GRADO-CAFFARO
Keyword(s):  
Optical Absorption ◽  
Absorption Coefficient ◽  
Far Infrared ◽  
Structural Disorder ◽  
Optical Absorption Coefficient ◽  
Infrared Range ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Operational Technique ◽  
Dynamical Disorder

By considering a sample of amorphous GaAs with a small zone of dynamical disorder, an expression for the optical absorption coefficient and phonon density of states in the low region of the far-infrared range is obtained. To get to this end, absorption corresponding to structural disorder is neglected.

MAXIMUM DYNAMICAL DISORDER IN AMORPHOUS GaAs

1994 ◽  
Vol 08 (03) ◽  
pp. 169-172 ◽  
Author(s):  
M.A. GRADO CAFFARO ◽  
M. GRADO CAFFARO
Keyword(s):  
Optical Absorption ◽  
Absorption Coefficient ◽  
Density Of States ◽  
Far Infrared ◽  
Conduction Band Edge ◽  
Infrared Range ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
Low Frequencies ◽  
Dynamical Disorder

Maximum dynamical disorder in amorphous gallium arsenide is investigated in a special way. In particular, this maximum disorder refers to distance and it is investigated in the context of optical absorption at very low frequencies in the far-infrared range when the photon energy is larger than 2Ec, Ec being the energy at the conduction band edge. Absorption coefficient is calculated and compared with experimental work. Phonon density of states is also evaluated.

AN ANALYTICAL FORMULATION FOR CALCULATING INFRARED ABSORPTION AND ELECTRICAL CONDUCTANCE IN AMORPHOUS SOLIDS

2006 ◽  
Vol 20 (29) ◽  
pp. 1853-1857 ◽  
Author(s):  
M. A. GRADO-CAFFARO ◽  
M. GRADO-CAFFARO
Keyword(s):  
Infrared Absorption ◽  
Cluster Model ◽  
Electrical Conductance ◽  
Far Infrared ◽  
Amorphous Solids ◽  
Infrared Range ◽  
Electronic Density ◽  
Analytical Formulation ◽  
Hückel Theory ◽  
Large Clusters

By employing a cluster model within the context of the extended Hückel theory, an analytical formulation is established by studying infrared absorption and electrical conductance in amorphous solids. This formulation is derived from considerations on electronic density of states. With respect to infrared absorption, the low region of the far-infrared range is analyzed for large clusters.

Sign in / Sign up

Export Citation Format

Share Document