We investigated time-resolved differential reflection in GaMnAs by pump-probe method at various wavelengths. The signals in GaMnAs were found to be more influenced by the compensating nature of the samples, rather than by the Mn concentrations. The time-resolved reflectivity of highly compensated samples exhibited stronger negative ΔR component at photon energies higher than the bandgap energy. This behaviour was similar to that of As+-ion implanted GaAs. Our results suggest that arsenic antisites (AsGa) act as deep donors as in low-temperature grown GaAs and play an important role in compensating holes in GaMnAs.
ASJC Scopus subject areas
- Condensed Matter Physics