Microphotoluminescence characterization of alloy fluctuations in InGaAsN/GaAs quantum wells emitting at 1.3 µm

Microphotoluminescence studies of annealed In( x) Ga( 1 - x) N( y) As( 1 - y)/ GaAs quantum wells fabricated by molecular beam epitaxy for optical emission in the 1.3 mu m spectral range revealed several sharp peaks about 2 - 7 meV wide in the emission spectra. The intensity of the discrete lines decreased strongly with increasing lattice temperature and was absent in as-grown ( unannealed) quantum wells. Such quantum dot-like emission lines are attributed to the recombination of excitons strongly localized at alloy fluctuations composed of In-N-rich clusters.