Structural and optical studies of ZnCdSe/ZnSe/ZnMgSSe separate confinementheterostructures with different buffer layers grown by molecular beam epitaxy

A great improvement of optical quality was observed from a ZnCdSe/ZnSe/ZnMg SSe single quantum well separate-confinement heterostructure grown on GaAs substrate with ZnSe/ZnCdSe strained-layer superlattices (SLS) buffer layers by molecular beam epitaxy. Transmission electron microscopy images showed that a pitted surface was generally formed after the desorption of GaAs sub strate in a II-VI chamber. However, this pitted surface was smoothed out by the growth of SLS buffer layer. Near room temperature photoluminescence in dicated that the carrier collection efficiency of quantum wells in the samp le with SLS buffer layer is better than the sample only with a ZnSe buffer layer. (C) 1999 Elsevier Science B.V. All rights reserved.