Effect of disorder-induced band mixing on the conduction-band effective mass of InAlGaAs alloys lattice matched to InP

It is found that the calculation of the effective mass for InAlGaAs alloys obtained from the five-band k . p theory is smaller than the measured value from the optically detected cyclotron resonance reported recently. We point out that the effect of disorder-induced conduction valence band mixing must be considered. This disorder effect which creates potential fluctuations is to reduce the matrix element P-2 for the conduction valence ba-nd coupling in the k . p theoretical expression. The strength of the potential fluctuations can be described in terms of the electronegativity difference related to chemical disorder. The inclusion of the disorder effect in the (In0.53Al0.47As)(x)(In0.53Ga0.47As)(1-x) quaternary system gives a very good fit to the measured data. (C) 1996 American Institute of Physics.