Nitrogen incorporation and optical studies of GaAsSbN/GaAs single quantum well heterostructures

Abstract

In this work, the effects of N incorporation on the optical properties of GaAsSbNGaAs single quantum wells (SQWs) have been investigated using temperature, excitation, and magnetic dependencies of photoluminescence (PL) characteristics. These layers were grown in an elemental solid source molecular beam epitaxy system with a rf plasma N source. The N concentrations in the range of 0.5%-2.5% were investigated in this study. The SQW with N∼0.5% exhibits a behavior similar to that in an intermediate regime where the contributions from the localized states in the band gap are dominant. The temperature and excitation dependencies of the PL characteristics indicate that for the N concentration of 0.9% and above, the alloy behavior is analogous to that of a regular alloy and the changes in optical properties are only marginal. The conduction band effective mass (meff) values computed from the magnetophotoluminescence spectra using a variational formalism and the band anticrossing model are in good agreement and indicate enhanced values of meff. However, there is no significant variation in meff values of QWs for N0.9%. Small redshift of about 30-50 meV for the temperature variations from 10 to 300 K in conjunction with unusually small blueshift observed in the excitation dependence of PL for N0.9% indicate that this system holds a great promise for laser applications at 1.55 μm and beyond. © 2007 American Institute of Physics