Hole capture into self-organized InGaAs quantum dots

Hole capture into and emission from self-organized InGaAs∕GaAs quantum dots (QDs) are studied by means of charge-selective deep level transient spectroscopy. The authors observe hole capture and determine activation energies and apparent capture cross sections for emission and capture. The experimental findings indicate that the capture process into the QDs in the presence of an applied electric field is controlled by phonon-assisted tunneling. An apparent capture cross section (at infinite values of temperature T and electric field F) σF,T=∞≈7×10−12cm2 and an average time tc≈0.3ps (T=300K) for hole capture and relaxation are obtained.