Carrier Dynamics In Particle-Irradiated Ingaas/Gaas Quantum Dots

The influence of high-energy (2.4 MeV) proton irradiation on the photo luminescence (PL), PIL excitation (PLE) and time-resolved PL (TRPL) spectra of InGaAs/GaAs quantum dot (QD) structures is investigated. A pronounced impact of the Fermi level, shifting towards the centre of the gap with increasing irradiation dose, is observed. The results evidence carrier tunnelling out of excited QD states to adjacent defects. It is suggested that for the dose range investigated in the study (less than or equal to10(14) p/cm(2)) the dots do not contain radiation defects.