Studies of free-to-bound acceptor photoluminescence in an applied magnetic field for undoped GaAs grown by metalorganic vapor-phase epitaxy and molecular-beam epitaxy

Abstract

Photoluminescence in an applied magnetic field is shown to be useful for the identification of trace acceptor impurities in GaAs. For an epitaxial layer grown by metalorganic vapor-phase epitaxy (MOVPE), a trace concentration of zinc acceptors was detected in a sample where the zinc transitions were obscured in zero magnetic field. In material grown by molecular-beam epitaxy (MBE), the 1.47-eV transition was identified as a conduction-band-to-deep-acceptor process. Also identified was a shallow impurity, magnesium or beryllium, not detected in zero field. Resolved Landau level transitions and the magnetic splitting of conduction-band-to-acceptor transitions were observed in both MOVPE and MBE material.