Molecular beam epitaxy of iron-doped HgSe layers

Abstract

We report on the growth and the iron doping of epitaxial HgSe layers by molecular beam epitaxy. The structural and the electronic properties of layers are characterized. The processes limiting growth rate are investigated, indicating that absorption and desorption are the limiting events of condensation. The full width at half maximum (FWHM) of the rocking curves is measured by high resolution X-ray diffraction (HRXRD). A critical thickness of about 200 nm is determined from FWHM measurements. This value is significantly larger than the equilibrium critical thickness given by the theory of Matthews and Blakeslee. The iron doping concentration is calibrated by Hall effect measurements. The layers are investigated with respect to the dependence of the electron mobility on the iron doping concentration by Hall effect and Shubnikov-de Haas measurements in magnetic fields up to 12 T. As in bulk material a strong increase of the Hall mobility is observed when the iron doping concentration exceeds a critical value of about 5*1018 cm-3. The maximum Hall mobility of 2.7*105 cm2 V-1 s-1 in our layers is to our knowledge one of the highest values measured in this material.