Identification of residual donors in high-purity undoped p-type epitaxial GaAs by magnetophotoluminescence

Abstract

The residual donor species, Si, S, and Ge, have been identified in high-purity undoped p-type epitaxial GaAs grown by metalorganic chemical vapor deposition and arsenic trichloride vapor phase techniques using the magnetic splittings of ‘‘two-electron’’ replicas of donor bound exciton transitions at low temperature (∼1.8 K) and at a high magnetic field (9.0 T). This technique permits identification of donors in certain high-purity p-type GaAs samples in which donor species cannot be identified by photothermal ionization spectroscopy or any other technique.