MOLECULAR-BEAM EPITAXY OF IRON-DOPED HGSE LAYERS

We report on the growth and the iron doping of epitaxial HgSe layers b y molecular beam epitaxy. The structural and the electronic properties of layers are characterized. The processes limiting growth rate are i nvestigated, indicating that absorption and desorption are the limitin g events of condensation. The full width at half maximum (FWHM) of the rocking curves is measured by high resolution x-ray diffraction (HRXR D). A critical thickness of about 200 nm is determined from FWHM measu rements. This value is significantly larger than the equilibrium criti cal thickness given by the theory of Matthews and Blakeslee. The iron doping concentration is calibrated by Hall effect measurements. The la yers are investigated with respect to the dependence of the electron m obility on the iron doping concentration by Hall effect and Shubnikov- de Haas measurements in magnetic fields up to 12 T. As in bulk materia l a strong increase of the Hall mobility is observed when the iron dop ing concentration exceeds a critical value of about 5 x 10(18) cm(-3). The maximum Hall mobility of 2.7 x 10(5) cm(2) V-1 s(-1) in our layer s is to our knowledge one of the highest values measured in this mater ial.