The effects of thermal annealing on the photoluminescence and DC characteristics of 1.3 µm p‐doped InAs/InGaAs/GaAs quantum dot lasers

Abstract

In this work, we investigated the optical characteristics of 1.3 µm p ‐doped InAs/InGaAs/GaAs quantum dot (QD) lasers that consist of either as‐grown or annealed QDs. With reference to the as‐grown QD lasers, it is found that 1) the integrated intensity of the photoluminescence could be increased by 63%, and 2) the onset of excited state lasing can be significantly delayed to a higher injection current with optimum annealing conditions. In addition, the internal quantum efficiency and internal optical loss of the annealed QD lasers has been improved. The observed improvements could be attributed to the removal of defects which act as nonradiative recombination centers in the QD structure and the reduction in the Auger‐related recombination processes upon annealing (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)