Recombination in a GaAs/Ga0.6Al0.4As heterostructure was studied by using optically and electrically detected magnetic resonance techniques. Optically detected magnetic resonance, performed at 35GHz, revealed the presence of Ga interstitials in a GaAs quantum well which was co-doped with Si and Be. Depending upon the contacts which were used, electrically detected magnetic resonance (performed at 9 and 34GHz) was able to detect surface defects and intrinsic defects (Ga interstitial and AsGa antisite). The location of paramagnetic states in the heterostructure was determined by means of electrically detected magnetic resonance; using light with various absorption lengths for the selective excitation of photoconductivity, together with phase-shift analysis of the various electrically detected magnetic resonance signals with respect to the modulation reference. By using X-band and Q-band detection, the defect parameters (g-factor and hyperfine constants) for the Ga interstitial were determined to be g = 2.006, A69 = 0.048/cm, and A71 = 0.061/cm.

Recombination centers in GaAs/Al0.4Ga0.6As heterostructures investigated by optically and electrically detected magnetic resonance T.Wimbauer, M.S.Brandt, M.W.Bayerl, N.M.Reinacher, M.Stutzmann, D.M.Hofmann, Y.Mochizuki, M.Mizuta: Physical Review B, 1998, 58[8], 4892-902