Influence of barrier doping and barrier composition on optical gain in (In,Ga)N MQWs

The influence of barrier doping and barrier composition on the optical gain in (In,Ga)N multiple quantum wells is studied under stationary conditions. Systematic temperature dependent gain measurements are performed by means of the variable-stripe-length method. Furthermore, PL spectra are recorded in order to study the temperature dependence of the quantum efficiency whic h gives information on activation processes to nonradiative recombination c hannels. The measured threshold densities and gain can successfully be expl ained by consideration of localization effects.