SUMMARY
The time-resolved photoluminescence of donor Si-doped GaAs/AlxGa1-xAs (x = 0.3 0.25, 0.2, 0.1) structures designed for microwave and terahertz detectors have been investigated at T = 3.6 K temperature. The excitonic, impurity and defect related emission lifetimes are revealed for these structures. Possible mechanisms of carrier recombination are discussed. Concentration of acceptor, carbon and silicon, are evaluated from measured lifetimes in the structures. DOI: http://dx.doi.org/10.5755/j01.ms.20.2.6317