Variations of the hole effective masses induced by tensile strain in ${\mathrm{In}}_{1\mathrm{-}\mathit{x}}$${\mathrm{Ga}}_{\mathit{x}}$As(P)/InGaAsP heterostructures

Magneto-optical experiments have been used to study a range of InGaAsP-based multiple-quantum-well (MQW) structures containing biaxial strains, ranging from 1.6% tensile to 1.0% compressive. The observed excitonic transitions, involving both heavy and light holes, are studied in fields up to 15 T. Estimates of the hole effective masses are made, providing details of the valence-band nonparabolicities, and electronlike behavior is demonstrated for both heavy and light holes with different amounts of tensile strain. This is related to band crossings within the valence band and enables an estimate of 0.68±0.10 to be made of the heterojunction band offset in a strained ${\mathrm{In}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Ga}}_{\mathit{x}}$As/InGaAsP MQW, with approximately 1.25% tensile strain in the well region. The experimental data are compared to the results of k⋅p Hamiltonian calculations of the in-plane valence-band dispersion.