Carrier dynamics in Beryllium doped low-temperature-grown InGaAs/InAlAs

The electron and hole dynamics in low-temperature-grown InGaAs/InAlAs multiple quantum well structures are studied by optical pump-probe transmission measurements for Beryllium (Be) doping levels between 3×10 17cm-3 and 4×1018cm-3. We investigate electron dynamics in the limit cases of unsaturated and completely saturated electron trapping. By expanding a rate equation model in these limits, the details of carrier dynamics are revealed. Electrons are trapped by ionized arsenic antisites, whereas recombination occurs between trapped electrons and holes trapped by negatively charged Be dopants.