Dc. Driscoll et al., Electronic structure and conduction in a metal-semiconductor digital composite: ErAs : InGaAs, APPL PHYS L, 78(12), 2001, pp. 1703-1705
We have grown epitaxial superlattice structures of layers of semimetallic E
rAs particles embedded in an InGaAs matrix on (001) Fe-doped InP substrates
. Temperature-dependent Hall measurements, x-ray diffraction, and transmiss
ion electron microscopy were performed on the materials. The carrier mobili
ty and the temperature dependence of the charge density imply conduction in
the InGaAs matrix. We calculate an offset between the conduction-band mini
mum of the InGaAs matrix and the Fermi level of the ErAs particles that is
strongly dependent on the amount of ErAs deposited. As the size of the ErAs
particles increases, the Fermi level decreases from similar to0.01 eV abov
e the InGaAs conduction-band edge to similar to0.2 eV below the InGaAs cond
uction-band edge and the electrical conduction properties change from metal
lic to semiconducting. (C) 2001 American Institute of Physics.