Growth and structural characteristics of (Ga,Al)As Bragg reflectors grown by MBE on nominal and vicinal (111)B GaAs substrates

MBE growth of(Ga,Al)As-GaAs Bragg reflectors on GaAs substrates with nomina l and vicinal 2 degrees off towards [2 (1) over bar (1) over bar] orientati ons has been optimized on the basis of atomic force microscopy and transmis sion electron microscopy analyses. Twins were found to be the main defects present in these multilayers. These defects were suppressed by using adequa te MBE growth conditions. This allowed us to obtain GaAs-(Ga,Al)As multilay ers with vicinal(1 1 1)B orientation having mirror-like surfaces and good r eflectivity, as required in optoelectronic devices. (C) 1999 Elsevier Scien ce B.V. All rights reserved.