Epitaxial growth and photoluminescence of AlAs/GaP short-period superlattices

(AlAs)(m)/(GaP)(n) short-period superlattices with (m, n) = (3, 3), (2, 3), (1,4) were grown on (0 0 1) GaAs substrates by gas-source migration-enhanc ed epitaxy at 400<^>C. The formation of the structures was confirmed by X-r ay diffraction measurements and cross-sectional transmission electron micro scopy analysis. A broad emission in the photoluminescence spectra was obser ved at approximately 550 560 nm in all the samples at low temperature. Tile origin of the peaks of the (AlAs)(3)/(GaP)(3) and (AlAs)(2)/(GaP)(3) sampl es was considered to be either the localization state or the energy band re flecting the zone-folding and band-mixing effect of the superlattices, whil e the peak of the (AlAs)(1)/(GaP)(4) sample was ascribed to defects in the layer or heterointerface roughness. (C) 2001 Elsevier Science B.V. All righ ts reserved.