Gudenko Y. The non-equilibrium charge carriers in the selectively doped heterostructures of GeSi/Si and InGaAs/GaAs with quantum wells.

The phenomena related to the non-equilibrium charge carriers in the selectively doped semiconductor multilayer heterostructures of GeSi/Si and InGaAs/GaAs with single and tunnel-coupled quantum wells experimentally investigated. In the structures of n-InxGa1-xAs/GaAs, the long-lasting relaxation of photoconductivity under the interband excitation is found. It is associated with localization and spatial separation of photo-generated charge carriers by the chaotic potential relief caused by fluctuations of the compound composition in the quantum wells. The dependences of the average relaxation time on the temperature and applied electric field as well as the dependence on the amplitude of the potential energy fluctuations are obtained. For the structures of p-GeSi/Si with the delta-doped wells, the persistent photoconductivity is described. It is explained by capture of the photo-excited charge carriers onto the defect traps in the barrier. The experimental data on the bipolar drift length and mobility of the non-equilibrium photo-generated carriers are obtained. The dependence of the boron shallow acceptor ionization energy on the position of the impurity center in the well is also obtained. Investigations of the charge carriers heating-up in the quantum wells of the n-InxGa1-xAs/GaAs heterostructures by the lateral electric field and features of transport and "hot" carriers emission were carried out. The light, emitted by charge carriers in course of their intraband indirect optical transitions, is polarized preferably along the field direction. This phenomenon is explained by the anisotropy of the distribution function of charge carriers which is induced by the electric field.