PHOTOINDUCED TRANSIENT SPECTROSCOPY OF DEEP LEVELS IN GAAS GA1-XALXASMULTIPLE-QUANTUM WELLS/

The capture and emission dynamics of deep levels in GaAs/Ga1-xAlxAs mu ltiple quantum well structures are investigated by using the photoindu ced transient spectroscopy technique, In nominally undoped samples thr ee trapping levels with activation energies in the range between 0.4 a nd 0.8 eV are observed. These are compared with the observations based on other conventional techniques. Large capture cross sections associ ated with the trapping centers implies that the presence of these can be detrimental for the high speed operation of optoelectronic devices based on GaAs/Ga1-xAlxAs quantum well structures. (C) 1997 American In stitute of Physics.