Quantum-well strain and thickness characterization by degree of polarization

InGaAsP/InP single quantum wells grown by gas-source molecular-beam epitaxy have been characterized for their strain and thickness using degree of polarization (DOP) of the edge emission photoluminescence at room 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 increases with a decrease in thickness of the well and as the strain varies from tension to compression. For example, we observe a variation of DOP from 20% to 79% when the strain varies from 1% tension to 1% compression for a 30 Å layer and from 27% to 62% when the thickness of a lattice-matched well is varied from 100 to 30 Å. A simple theoretical model is used to predict this trend. We show that this technique provides a sensitive measure of the variations in the strain and thickness of quantum wells.