Arsenic pressure and spacer layer thickness effects on the optical properties of stacked InAs/InAlAs quantum dot array



We report on investigations of InAs/InAlAs/InP stacked quantum dots (QDs). The photoluminescence spectroscopy (PL) and time resolved photoluminescence spectroscopy (TRPL) results, have shown an increase of the radiative life time and an important red shift of the PL band with decreasing the spacer layer thickness. The observed effects are explained as a consequence of the electronic coupling between vertical ordered QIs. The PL results have also shown that the emission from these structures depends not only upon the spacer thickness but also on the arsenic pressure. For spacer layer thickness equal to 10 nm and arsenic pressure equal to 5.5 10–6 Torr we have a more homogenous organisation of the formed nanowires. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)