Optical Absorption and Temperature-Dependent Resistivity of GaMnN Grown by Molecular Beam Epitaxy

Abstract

GaMnN layers grown by molecular beam epitaxy were characterized by current-voltage, temperature-dependent resistivity, and optical absorption measurements. Transitions from the Mn acceptors to the conduction band were observed in optical absorption spectra, corresponding to an energy level of E C - 1.9 eV. Electrical measurements showed the material to be high resistivity (3.2 X 10 7 Ω cm) n-type for the 3 atom % Mn concentration, with the Fermi level controlled by defects or impurities with an activation energy of 0.1 eV. Under these conditions, the GaMnN showed the highest degree of ordering per Mn atom in magnetometry measurements.