We measured the transmission spectra and the time-resolved differential reflectivity ΔR in Ga 1-xMn xAs for x≤0.05 for several excitation wavelengths. The sign of ΔR in Ga 1-xMn xAs (x =0.015 and x=0.03) was negative for photon energy larger than band gap at room temperature. The negative component of ΔR was explained by defect induced absorption and/or the reduction of exciton bleaching, rather than by the change in density of near band edge states associated with Mn incorporation. For Ga 0.95Mn 0.05As, absorption edge broadening was observed in the transmission spectra and the induced absorption effect was reduced by the screening of Mn local potential by photocarriers.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)