Radiation hardness of InGaAs/GaAs quantum dots

The interaction between point defects in the matrix and excitons localized in self-organized InGaAs/GaAs quantum dots is investigated for structures irradiated by protons. The exciton ground state is demonstrated to be unaffected by radiation doses up to 10(14) p/cm(2). The close proximity of radiation-induced defects leads to a strong nonmonotonous temperature dependence of the luminescence yield: Carriers are lost via tunneling from excited quantum dot states to irradiation-induced defects below similar to100 K, whereas at higher temperatures, carriers escape to the barrier and are captured by defects. (C) 2003 American Institute of Physics.