TIME-RESOLVED STUDY OF CARRIER CAPTURE AND RECOMBINATION IN MONOLAYERBE DELTA-DOPED GAAS

The first measurements of subpicosecond dynamics of carrier capture an d decay in Be delta-doped GaAs structures with p-doping density rangin g from 6x10(12) to 2X10(14) cm(-2) and spatial distribution on monolay er scale show that photoexcited carriers are captured in the delta-dop ed layer in <1 ps. Luminescence decay rates show a strong dependence o n energy of the hole in the two-dimensional Fermi gas. We attribute th is to a change in the spatial electron-hole overlap resulting from ban d-mixing effects. We show that Be density fluctuations lead to strong carrier localization. (C) 1995 American Institute of Physics.