Electronic properties and optical-absorption spectra of graded-gap GaAs-AlxGa1−xAs quantum wells

1987 ◽  
Vol 36 (9) ◽  
pp. 4849-4857 ◽  
Author(s):  
G. D. Sanders ◽  
K. K. Bajaj
Keyword(s):  
Optical Absorption ◽  
Quantum Wells ◽  
Electronic Properties ◽  
Absorption Spectra ◽  
Optical Absorption Spectra

scholarly journals Photoelectrochemistry of Ferrites: Theoretical Predictions vs. Experimental Results

2020 ◽  
Vol 234 (4) ◽  
pp. 719-776 ◽  
Author(s):  
Anna C. Ulpe ◽  
Katharina C.L. Bauerfeind ◽  
Luis I. Granone ◽  
Arsou Arimi ◽  
Lena Megatif ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Electronic Properties ◽  
Absorption Spectra ◽  
Raman Spectra ◽  
First Principles ◽  
Experimental Results ◽  
Atomic Scale ◽  
Optical Absorption Spectra ◽  
Photoelectrochemical Activity

AbstractThis paper gives an overview about recent theoretical and experimental work on electronic and optical properties of spinel ferrites MFe2O4. These compounds have come into focus of research due to their possible application as photocatalyst material for photoelectrochemical water splitting. The theoretical background of state-of-the-art quantum-chemical approaches applied for predicting electronic and optical band gaps, absolute band positions, optical absorption spectra, dielectric functions and Raman spectra, is briefly reviewed. Recent applications of first-principles methods on magnetic and electronic properties of ferrites with M = Mg and the first row of subgroup elements Sc to Zn are presented, where it is shown that the fundamental band gap is strongly dependent on the spin state and the degree of inversion of the spinel structure. The observed variation of electronic properties may serve as an explanation for the large scattering of experimental results. The exchange of M and Fe cations has also a pronounced effect on the Raman spectra of ferrites, which is analyzed at atomic scale from first principles. Calculated optical absorption spectra of ferrites are compared to experimental spectra. The electronic nature of the first excitations and the role of oxygen vacancies are discussed. For the calculation of absolute band positions, which have a significant impact on the photoelectrochemical activity of the ferrites, models of the most stable ferrite surfaces are developed that take into account their polar nature and the interaction with the solvent. Theoretically predicted valence and conduction band edges are compared to results from electrochemical measurements. The role of cation exchange on the surface electronic structure is investigated both theoretically and experimentally.

Donor-related magneto-optical absorption spectra of GaAs - (Ga, Al)As quantum wells

1997 ◽  
Vol 9 (15) ◽  
pp. 3181-3187 ◽  
Author(s):  
L H M Barbosa ◽  
A Latgé ◽  
L E Oliveira ◽  
M de Dios-Leyva
Keyword(s):  
Optical Absorption ◽  
Quantum Wells ◽  
Absorption Spectra ◽  
Optical Absorption Spectra
Sign in / Sign up

Export Citation Format

Share Document