Effects of Tensile Strain on Band Offsets in Ingaasp/Inp Quantum Wells
The effects of tensile strain on valence band offsets in InxGa1- xAs0.51P0.49/InP quantum wells, are calculated using tight binding method. The valence band offset for x = 1 is 0.40eV and for x = 0 is 0.81eV. A model for calculating valence band offset dependence on tensile strain is proposed. The difference in valence band offset for tensile strained layers at 0.5% and 0% is 29meV, which is in good agreement with the experiment. As the tensile strain increases the valence band offset increases, linearly. The intercept represents the valence band offset at the onset of lattice mismatch, whereas the slope represents the difference between the bond length of the sub-strate and the average bond length of the compounds that make up the epilayer.