Title |
Berilio ir silicio priemaišų įtaka GaAs/AlAs kvantinių šulinių spinduliuotei / |
Translation of Title |
Effect of beryllium and silicon impurities on radiation from GaAs/AlAs quantum wells. |
Authors |
Čerškus, Aurimas |
Full Text |
|
Pages |
114 |
Keywords [eng] |
quantum well ; GaAs/AlAs ; δ-doped ; photoluminescence ; exciton |
Abstract [eng] |
The dissertation focuses on the investigation of photoluminescence spectra of Be acceptor and Si donor impurities δ-doped GaAs/AlAs multiple quantum wells from liquid helium to room temperature. Binding energies of impurities and excitons bound to impurities were measured experimentally. The influence of the impurities on the intrinsic radiation was determined. An asymmetry of lineshape of impurity related radiation was shown both experimentally and theoretically. The phonon replicas of impurity related radiation were found, and the strength of interaction of impurity related radiation with LO phonon has been valued. A fractional-dimensional space approach has been applyed for theoretical interpretation of the results. A change of photoluminescence spectra with increasing impurity concentration has been explored. It was shown that new energy-level structure forms in p-type δ-doped GaAs/AlAs quantum wells after the occurrence of the dielectric-metal Mott transition. The impurity concentrations when Mott transition occur has been estimated experimentally and evaluated theoretically. |
Type |
Doctoral thesis |
Language |
Lithuanian |
Publication date |
2009 |