MOLECULAR-BEAM EPITAXY OF ZNS ON (001)GAAS USING ELEMENTAL SOURCES

ZnS epilayers have been grown by molecular beam epitaxy on (001) GaAs from elemental zinc and sulphur sources. Reflection high-energy electron diffraction (RHEED) measurements were performed to study the surface reconstruction of (001) ZnS and to establish a surface reconstruction diagram in order to find the optimum growth conditions. The dependence of the growth rate of ZnS on the substrate temperature and on the beam pressure ratio p(s)/p(Zn) has been measured. The strain relaxation of the ZnS epilayers was determined by high-resolution RHEED measurements. The tow-temperature photoluminescence spectra of the ZnS epilayers show sharp ultraviolet exciton lines and a blue deep-centre emission.