The structural and the optical properties of cubic GaInN MBE-grown on GaAs
substrates are investigated using scanning electron- and cathodoluminescenc
e microscopy, time-resolved and time-integrated photoluminescence spectrosc
opy as well as gain measurements at 2 K and 300 K. The In content is rangin
g from 3% to 30%. From the carrier dynamics localized states are proposed t
o be responsible as recombination mechanism. From temperature- and intensit
y-dependent gain measurements, the identification of the gain processes was
possible. Optical gain values up to 60 cm(-1) were observed at wavelengths
up to 500 nm, indicating the advantage of this material system due to the
lack of detrimental pyro- and piezoelectric fields. The degree of In fluctu
ations directly determines the optical quality and the efficiency of optica
l amplification of the samples.