Relevance of the purity level in a MetalOrganic Vapour Phase Epitaxy   reactor environment for the growth of high quality pyramidal sitecontrolled   Quantum Dots
  We report in this work on the spectral purity of pyramidal site-controlled InGaAs/AlGaAs Quantum Dots grown by metalorganic vapour phase epitaxy on(111)B oriented GaAs substrates. Extremely sharp emission peaks were found, showing linewidths surprisingly narrow (~27{\mu}eV) and comparable to those which can be obtained by Molecular Beam Epitaxy in an ultra-high vacuum environment. A careful reactor handling is regarded as a crucial step toward the fabrication of high optical quality systems. 
Valeria Dimastrodonato, Lorenzo O. Mereni, Robert J. Young and   Emanuele Pelucchi
cond-mat.mtrl-sci