The temperature dependence of band gap energies of GaAsN alloys was studied
with absorption measurements. As the N concentration in GaAsN increased, t
he temperature dependence of the band gap energy was clearly reduced in com
parison with that of GaAs. The redshift of the absorption edge in GaAsN for
the temperature increase from 25 to 297 K was reduced to 60% of that of Ga
As for the N concentration larger than similar to 1%. The differential temp
erature coefficient of the energy gap at room temperature was also reduced
to 70% of that of GaAs. The main factor for this reduced temperature depend
ence in GaAsN was attributed to the transition from band-like states to nit
rogen-related localized states with detailed studies of the temperature-ind
uced shift of the absorption edge. (C) 2000 American Institute of Physics.
[S0003-6951(00)04110-3].