Molecular-beam epitaxial growth and characteristics of highly uniform InAs/GaAs quantum dot layers

Abstract

We have investigated the molecular-beam epitaxial growth and structural and photoluminescence characteristics of self-organized InAsGaAs quantum dot bilayers, in which a first seed layer of stressor dots is followed by a GaAs barrier layer and a second layer of active dots. At room temperature, the peak emission wavelength is at ∼1.4 μm. By optimizing the growth parameters for both dot layers and the GaAs barrier layer, we have measured photoluminescence linewidths of 10.6 and 17.5 meV at 20 and 300 K, respectively. The measurement and analysis of temperature-dependent photoluminescence data indicate that there is no observable carrier redistribution amongst the dots with an increase of temperature and there is a high degree of size uniformity. The photoluminescence linewidth of 17.5 meV at 300 K is almost identical to that measured in the emission from a single dot, indicating that the linewidth is determined by homogeneous broadening. © 2005 American Institute of Physics.