Electronic Properties of Dislocations in Heavily Dislocated Quantum Well Structures: Doping Effects.

摘要

In heavily dislocated GaAs (dislocation density of 108 cm-2), the low-temperature cathodoluminescence efficiency of quantum wells and superlattices is dramatically higher than that of a bulk-like layer. Furthermore, the luminescence efficiency can be further improved by doping the barriers of the GaAs/(A1,Ga)As multiquantum well structures with beryllium (Be). Two quite different possible models for this observation are discussed: One assumes that the effect is due to the expulsion of dislocation kinks from the wells, the other that it is due to the effect of well width fluctuations. Keywords: GaAs, Gallium arsenide, Si, Silicon, Dislocations, MBE, Molecular beam epitaxy. Reprints. (JES)