INTRADOT CARRIER RELAXATION IN RADIATION-DAMAGED InGaAs/GaAs QUANTUM DOT HETEROSTRUCTURES

摘要

The influence of high-energy (2.4 MeV) proton irradiation on the photoluminescence (PL), PL excitation and time-resolved PL spectra of InGaAs/GaAs quantum dots (QDs) is reported. The effect of irradiation on the PLE spectra is mainly attributed to a Fermi level shift towards the center of the gap. TRPL measurements show an evidence of carrier tunneling out of the excited QD states to adjacent defects. The ground level remains unaffected by the defects, at least up to a certain dose. Our considerations show that the dots very probably expulse radiation defects.