OPTICAL-PROPERTIES OF ZNSE1-XSX EPILAYERS GROWN ON MISORIENTED GAAS SUBSTRATES

The strain induced heavy hole and light hole exciton splitting of ZnSe 1-xSx (x<0.1) epilayers grown on misoriented GaAs (001) substrates has been studied by reflectance spectroscopy. The heavy hole and light ho le exciton energies are determined by the composition of the layers. I t was concluded that for both thin (largely unrelaxed strain) and thic k epilayers (with largely relaxed strain) misorientation of the substr ate results in increase of x, i.e., in increasing incorporation of sul phur. However, the additional strain expected due to the increasing in corporation of sulphur with misorientation was not observed due to par tial strain relief of the epilayers grown on misoriented substrates. T he optical quality of the epilayers is tilt angle dependent and is bes t for about 10 degrees tilt from the (001) direction. (C) 1998 America n Institute of Physics. [S0021-8979(98)09116-6].