Electron-hole scattering in highly doped p-GaAs after femtosecond optical excitation
The ultrafast relaxation of minority electrons in highly doped p-GaAs ( rho =1.0*1019cm-3) has been investigated through femtosecond lime-resolved luminescence. For low excitation densities the hole plasma temperature stays at 300 K and the transient luminescence spectra reveal the rapid cooling of the minority electrons within the first picoseconds. The electron-hole energy transfer is much larger (up to 10-7W) than the known electron-LO phonon scattering rate, which allows the quantitative determination of the electron-hole energy transfer.