Epitaxial dysprosium phosphide grown by gas-source and solid-source MBE on gallium arsenide substrates

Abstract We report the first known study of the growth of epitaxial dysprosium phosphide (DyP) grown on gallium arsenide (GaAs). DyP is lattice matched to GaAs, with the room-temperature mismatch being less than 0.01%. We have grown DyP on GaAs by gas-source and by solid-source molecular beam epitaxy using custom-designed group V thermal cracker cells and group III high temperature effusion cells. X-ray diffraction results show the DyP epilayer to be (001) single crystal on GaAs(001) substrate. Electrical and optical measurements performed to date are inconclusive as to whether DyP is a semi-metal or a semiconductor with a small band gap. The undoped films are n-type with measured electron concentrations on the order of 5 × 10 19 –6 × 10 20 cm −3 with mobilities of 1–10 cm 2 /V · s. DyP GaAs is stable in air with no apparent oxidation taking place, even after months of exposure to ambient untreated air. Material and surface science properties measured for DyP GaAs include Hall measurements, 2ϑ and double-crystal X-ray diffraction spectra and photothermal deflection spectroscopy.