On deep levels in high-resistivity LEC-GaAs investigated by means of photo induced current transient spectroscopy

In order to study deep defects in undoped LEC-grown GaAs, photo induced current transient spectroscopy (PICTS) has been carried out on materials with a depletion region. Five main traps were observed. In addition to positions in the gap, it is shown that the nature of carrier traps can also be identified. Contributions from the surface and the bulk of the material in the PICTS signal, are compared. Also, effects from the excitation light wavelength on PICTS spectra, are reported.