QUANTUM-WELL STRAIN AND THICKNESS CHARACTERIZATION BY DEGREE OF POLARIZATION

InGaAsP/InP single quantum wells grown by gas-source molecular-beam ep itaxy have been characterized for their strain and thickness using deg ree of polarization (DOP) of the edge emission photoluminescence at ro om temperature. The DOP is a measure of the relative strengths of TE- and TM-polarized e-hh and e-lh transitions. The value of the DOP incre ases with a decrease in thickness of the well and as the strain varies from tension to compression. For example, we observe a variation of D OP from 20% to 79% when the strain varies from 1% tension to 1% compre ssion for a 30 Angstrom layer and from 27% to 62% when the thickness o f a lattice-matched well is varied from 100 to 30 Angstrom. A simple t heoretical model is used to predict this trend. We show that this tech nique provides a sensitive measure of the variations in the strain and thickness of quantum wells. (C) 1996 American Institute of Physics.