High pressure experiments on Al xGa 1-xAs-GaAs quantum-well heterostructure lasers

Hydrostatic pressure experiments on Al _xGa _1-xAsGaAs quantum-well heterostructure (QWH) laser diodes are described. Data are presented giving ∼11.5meV/kbar for the bandgap vs. pressure coefficient at lower pressures, with a change to 8.5-9meV/kbar at higher pressures. We suggest that this behavior is caused by biaxial and shear stresses in the active region induced by doping or composition mismatch relative to the confining layers, or between the n and p confining layers themselves. A model consistent with the experimental data is presented.