Improved hole confinement in GaInAsN-GaAsSbN thin double-layer quantum-well structure for telecom-wavelength lasers

In this work we demonstrated increased hole confinement in a bilayer quantum well that consists of two thin layers of GaInAsN/GaAsSbN confined by GaAs barriers. Comparison between the temperature dependence of photoluminescence intensity of the bilayer and GaInAsN quantum wells indicated that electrons rather than holes are the less confined carriers in the bilayer structure. This structure enables independent control of the band gap energy, band offsets and reduces the temperature sensitivity of laser performance. The calculations showed that a bilayer based short-period superlattice would provide a high optical gain at 1.3-1.55 μm due to increased electron-hole wave functions overlap.