Effects of interdiffusion-induced strain in Ga _0.51In _0.49P-GaAs intermixed quantum wells

The effects of interdiffusion and strain introduced by interdiffusion in lattice-matched GaInP-GaAs single quantum wells are investigated using an error function distribution to model the compositional profile after interdiffusion. Group-III only and dominant group-III interdiffusion produce a large strain build up at the interface, with compressive strain in the well, and tensile strain in the barrier. In the case of group-III only interdiffusion, an abrupt carrier confinement profile is maintained even after significant interdiffusion, with a double- welled bottom, and a potential buildup in the barrier near the interface. Group-V only and group-V dominant interdiffusion again cause a large strain buildup at the interface, with tensile strain in the well and compressive strain in the barrier. Degeneracy of the heavy-hole and light-hole ground states can be achieved, and the electron-light-hole ground state transition energy can also become the effective bandgap energy of the intermixed structure. The model results are consistent with reported experimental results, and show that the effects of the interdiffusion-induced strain on the carrier confinement profiles can be of interest for various quantum-well device applications in this material system, including intersubband infrared photodetectors, polarization-insensitive electroabsorption modulators, and lasers.