Photoluminescence of Si δ-doped InGaAs/GaAs heterostructures with double beam excitation

Photoluminescence (PL) of the undoped In_0.2Ga_0.8 As/GaAs ans selectively Si δ-doped In_0.2Ga_0.8As/GaAs heterostructures with double excitation beams (He-Ne laser and white light) has been investigated. The increment of PL, which is the difference between the PL intensity with and without the white light, is obviously enhanced with an additional white light beam. PL increment of the undoped sample was the largest among all the samples. The increment for the samples with barrier doping is not as large as the undoped sample but more than the samples with doping in the quantum well. The PL increment of all the samples has shown the saturation behavior. The saturation is more pronounced for doped samples. An effective carrier density model is proposed to explain the experimental results