Energy Relaxation Dynamics In Vertically Coupled Multi-Stacked Inasgaas Quantum Dots

Effect of GaAs spacer layer thickness (d(GaAs)) on carrier capture, and the relaxation process is studied in multi-stacked InAs/GaAs quantum dots by photoluminescence and time-resolved photoluminescence. Auger scattering is the dominating process for carrier relaxation above d(GaAs) of 15 nm. At d(GaAs) of 10 nm, the carrier relaxation process is faster due to the combined effect of both single longitudinal optical phonon and Auger scattering resulting in higher photoluminescence intensity. The photoluminescence rise time corresponding to carrier capture and relaxation in quantum dots is longer at 3.06 eV excitation than that at 1.53 eV due to the effect of intervalley scattering in GaAs. Published by AIP Publishing.