COMPARISON OF THE QUANTUM-CONFINED STARK-EFFECT FOR (100)A-ORIENTED AND (311)A-ORIENTED GAAS ALGAAS QUANTUM-WELLS USING ELECTROREFLECTANCE SPECTROSCOPY/

The excitonic subband transitions of (100)- and (311)A-oriented GaAs/A lGaAs single quantum wells (SQW's) are investigated using electrorefle ctance spectroscopy. The strong Franz-Keldysh-Oscillations arising fro m the undoped AlGaAs barrier layers are analyzed to determine the fiel d strength within the SQW's directly from the measurements with high a ccuracy. Both, the orientation-dependent splitting between the first h eavy and light hole subbands and their field-induced shifts are compar ed with the results of k . p calculations. Best agreement between expe riment and theory is obtained for a set of Luttinger parameters corres ponding to heavy and light hole masses of 0.55m(0) and 0.084m(0), resp ectively, along the [311] direction. (C) 1995 Academic Press Limited