Enhanced degradation resistance of quantum dot lasers to radiation damage

We compare the degradation of InAs/GaAs quantum well (QW) and quantum dot ( QD) laser diodes following irradiation by high energy (8.56 MeV) phosphorou s ions. Over a fluence range of 10(8)-10(11) ions/cm(2), the degradation of the low temperature QD photoluminescence and electroluminescence emission is greatly suppressed relative to that of QW based devices (X100 and x 1000 , respectively at the highest dose studied). Irradiated QD laser diodes dem onstrated lasing action over the entire range of fluences, and 2 orders of magnitude beyond the maximum dose sustainable by QW devices. The improved d amage response of QD based structures results from efficient collection and localization of electrons and holes by QDs in the active region, which lim it carrier transfer to nonradiative centers. This work suggests the suitabi lity of QD device architectures for use in radiation environments, and in h igh power applications, wherever nonradiative processes promote the degrada tion or failure of traditional QW devices. (C) 2000 American Institute of P hysics. [S0003-6951(00)03231-9].