Heating of cold electrons by a warm GaAs lattice: A novel probe to carrier-phonon interaction.

The polar optical scattering of electrons and holes is studied by picosecond luminescence in a GaAs/Al sub x Ga sub (1-x) As heterostructure and in 5 and 13 nm thick GaAs/Al sub x Ga sub (1-x) As quantum wells. In contrast to earlier work we do not trace the cooling of hot carriers in a cold lattice but we look at the reverse process of heating of a cold electron- hole plasma by a warm lattice. The scattering rates prove to be independent of density, dimensionality, and quantum well thickness.