HOMOGENEOUS AND DELTA-DOPED ZNS-MN GROWN BY MBE

An investigation is reported on the growth of homogeneously and delta- doped ZnS:Mn layers. Bath undoped and Mn-doped ZnS thin films were gro wn by MBE and GSMBE using a sulfur overpressure. Photoluminescence mea surements on undoped material indicated that high crystal quality was obtained, with band edge emission intensity several orders of magnitud e higher than that from the self-activation peak. for a growth tempera ture of 180 degrees C. Homogeneously doped ZnS:Mn films showed a maxim um brightness at a Mn concentration of 3 mol% before luminescence quen ching was observed. The delta-doping technique was shown to quadruple the photoluminescence intensity compared to equivalently doped homogen eous material grown under the same conditions. The optimum distance be tween doping planes for a constant in-plane concentration was found to be 9-15 nm. SIMS studies of the diffusion behavior of Mn into the und oped ZnS layers revealed broad Mn peaks with a FWHM of about 10 nm.