INTERSUBBAND RELAXATION IN MODULATION-DOPED MULTIPLE-QUANTUM-WELL STRUCTURES

Photoexcited carrier behavior in modulation-doped multiple narrow GaAs -AlxGa1-xAs quantum-well structures which vary in quantum-well width a nd doping concentration is investigated with Monte Carlo simulations. The model includes scattering of Gamma-valley subband electrons by con fined slab and interface-polar-optical phonons and between Gamma-valle y and L-valley electrons via optical-deformation-potential phonons. Th e model closely predicts time constants for electron relaxation found experimentally and shows that the effect of including the L-valley tra nsitions in the Monte Carlo simulation is essential.