Barrier-doped ZnSe:Te-(CdSe)_m(ZnSe)_nshort-period superlattice quantum wells: atomic layer epitaxial growth and optical properties

Abstract

Barrier-doped ZnSe:Te-(CdSe)m(ZnSe)n short-period superlattice quantum wells (BDSPSQW) with isoelectronic Te elements have been fabricated by means of atomic layer epitaxy. Luminescence from BDSPSQW was strongly modified by spatially selective introduction of Te isoelectronic centres in the barrier. Free-quantum-well and self-trapped excitons can coexist over a wide range of temperatures because they are separated from each other spatially. Room-temperature luminescence was dominated by narrow recombination of quantum-well excitons. This phenomenon is discussed in terms of doping position and doping density, using the model of exciton extrinsic self-trapping.