Spin and charge effects caused by positively charged acceptors in GaAs/AlGaAs quantum wells
P.V. Petrov, Y.L. Ivanov, and N.S. Averkiev
A.F. Ioffe Physico-Technical Institute RAN, 26 Politekhnicheskaja Str., St.-Petersburg 194021, Russia
Received October 20, 2014
Optical data on GaAs/AlGaAs quantum well structures with positively charged acceptors (A+ centers) are presented. The magneto-optical measurements have provided information on spin structure and localization in the 2D system of A+ centers. The temperature properties of photoluminescence were used to study the energy structure of the A+ band. The analysis of all experimental data obtained by different optical methods and their comparison with the results of transport measurements given in literature made it possible to a unified physical picture of charge and spin phenomena in such systems. A new approach has been proposed that permits the Coulomb gap appearing at low temperatures in the density of localized states to be studied by using optical measurements.
PACS: 73.21.Fg Quantum wells; PACS: 71.23.–k Electronic structure of disordered solids; PACS: 73.90.+f Other topics in electronic structure and electrical properties of surfaces, interfaces, thin films, and low-dimensional structures.