Published online by Cambridge University Press: 25 February 2011
The photoluminescence of GaAs/Si grown by OMCVD has been analyzed as a function of temperature and the dominant high temperature line identified as a conduction-band-to-valence-band transition. Photoluminescence excitation spectra indicate that the transition is excitonic at 4.2 K. A second line, also identified as intrinsic, dominates the spectra below 100 K. A biaxial tensile strain is proposed to account for the two intrinsic lines through a splitting of the valence band degeneracy.