Transient-capacitance-spectroscopy experiments yielded electron-emission-rate and electron capture cross-section versus temperature data for the main electron trap in vapor-phase epitaxial ${\mathrm{Ga}}_{1-x}{\mathrm{In}}_x\mathrm{As}$ layers with $0<x<\mathrm{}0.21\mathrm{}$. The ionization energy $E_C-E_T$ was obtained from these. Theoretical calculations using the pseudopotential method were performed for substitutional oxygen donor in GaInAs, and the calculated energy levels were compared with the experimental ones. The electron-capture cross sections, as well as optical photoionization data are also discussed from the theoretical point of view. It is argued that most of the experimental evidence is not consistent with the idea that the observed electron trap is simple (substitutional) donor oxygen.

• Received 11 February 1977

DOI:https://doi.org/10.1103/PhysRevB.16.3665