OPTIMIZATION OF STRAINED SHORT-PERIOD ZNSSE ZNSE SUPERLATTICES GROWN BY METALORGANIC VAPOR-PHASE EPITAXY/

Series of ZnSe/ZnSxSe1-x strained-layer superlattices with x=0.1-0.14 grown by MOVPE using either diethylsulphide (DES) or hydrogen sulphide (H2S) as the sulphur source have been studied with X-ray double-cryst al diffractometry and photoluminescence. The effects of period thickne ss, number of periods, growth interruption and stabilization of the Zn SSe-to-ZnSe interface as well as buffer layers on the structural and o ptical properties were determined. These data serve as basis for optim ization of the growth parameters. High quality material was obtained a s indicated by narrow peak widths and numerous satellite peaks in the X-ray diffraction profiles for optimized samples grown with DES (120 p eriods, without stabilization, without buffer). Highly efficient blue luminescence at 2.7 eV observed at room temperature confirms the excel lent properties of the heterostructures. Because of the high resolutio n of the double-crystal X-ray diffraction we were enabled to detect ve ry small variations of layer thickness and composition in the superlat tice systems.