Home  About us  Contact
 

Disordered Semiconductors (disordered + semiconductor)

Distribution by Scientific Domains
Physics and Astronomy100%

Selected Abstracts

Localization of excitons in weakly disordered semiconductor structures: A model study

ANNALEN DER PHYSIK, Issue 12 2009
N. Gögh
Abstract Localization of the center-of-mass (com) motion of an exciton in a disordered semiconductor structure is studied theoretically by focusing on nonlinear optical spectroscopy. A one-dimensional tight-binding model with diagonal disorder is applied and the Coulomb interaction is treated consistently. In the ordered situation the center-of-mass momentum (K) selection rule leads to only the lowest transition for K = 0. The break down of the com-K-selection rule produces the well known asymmetric excitonic lines of disordered semiconductors. The coupling between the lowest dominant transition to this modified com-continuum yields Fano-like features in the nonlinear spectra. [source]

Potential fluctuations in disordered semiconductors measured by transport and optical methods

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2004
P. Bozsoki
Abstract From the recent analysis of the potential fluctuations in disordered semiconductors on the basis of optical and transport measurements [1] it was concluded that these two different kinds of phenomena evidence extremely different energy scales of the random potential in the same sample. We resolve this puzzle using for the analysis of experimental data the well-known theories of transport and optical absorption in a disordered system with long-range potential fluctuations, caused by charged impurities [2, 3]. The key point in our consideration is the essential difference between the density of states caused by the long-range fluctuations and the shape of the absorption coefficient. The latter is known to depend essentially not only on the fluctuation probability but also on the tunnelling efficiency of the optically excited electrons in the potential relief provided by the fluctuations [2]. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Localization of excitons in weakly disordered semiconductor structures: A model study

ANNALEN DER PHYSIK, Issue 12 2009
N. Gögh
Abstract Localization of the center-of-mass (com) motion of an exciton in a disordered semiconductor structure is studied theoretically by focusing on nonlinear optical spectroscopy. A one-dimensional tight-binding model with diagonal disorder is applied and the Coulomb interaction is treated consistently. In the ordered situation the center-of-mass momentum (K) selection rule leads to only the lowest transition for K = 0. The break down of the com-K-selection rule produces the well known asymmetric excitonic lines of disordered semiconductors. The coupling between the lowest dominant transition to this modified com-continuum yields Fano-like features in the nonlinear spectra. [source]