Dynamics of free carriers – neutral impurity related optical transitions in Be and Si δ-doped GaAs/AlAs multiple quantum wells: Fractional-dimensional space approach
Keywords: quantum well, photoluminescence, lifetime, capture cross-sections
AbstractThe dynamics of impurity-related optical transitions in 20 nm wide silicon and beryllium δ-doped GaAs/AlAs multiple quantum wells with various doping levels has been investigated at near liquid helium temperatures. The radiative lifetimes of the free electron-neutral acceptor and the free hole-neutral donor have been identified. The capture cross-sections of the free electrons by neutral Be acceptors were experimentally determined to σe-Be = 4 × 10–10 cm, whereas this corresponded to σh-Si = 2.2 × 10–8 cm for the free holes by neutral Si donors. The experimentally determined cross-section ratio of σh-Si/σe-Be = 55 is close to the estimated 2D value of σh-D/σe-A = 64 and remains lower compared to the calculated value for the 3D case of σh-D/σe-A = 121.
Condensed Matter Physics and Technology