Carrier diffusion in InAs/GaAs quantum dots and itsimpact on light emission from etched microstructures

摘要

Carrier diffu diffusion is investigated in InAs/GaAs quantum dotssion (QDs) and InGaAs/GaAs quantum well (QWs) in the 77 to 297 Ktemperature range. The measured carrier diffusion length is less in the QDlayer than the QW at all temperatures due to localisation of carriers indiscrete dots, with diffusion lengths of 6.5 iscrete mm and 9.5 mm measured atroom temperature. Carrier diffusion is completely suppressed in the QDlayer at temperatures less than 150K. The reduced carrier diffusion in theQD layer is shown to reduce non non-radiative edge recombination in deeplyetched microstructures. However edge effects still dominate carrierrecombination processes in a 3.2 mm diameter etched microstructurecontaining QDs at room temperature.