Effect of GaAs(001) surface misorientation on the emission from MBE grown InAs quantum dots

The photoluminescence (PL) is used to study the capped InAs quantum dot (QD ) single sheet array MBE grown on the vicinal GaAs(0 0 1) surfaces misorien ted to the [0 1 0] direction by 0 degrees, 2 degrees, 4 degrees, 6 degrees. The misorientation leads to thp blue shift and the narrowing of InAs QD PL lines and makes PL efficiency higher. These effects are related, respectiv ely, with the smaller size and higher size uniformity of the InAs QDs and r eduction of the number of large InAs islands on the misoriented surfaces. I t was found that the decrease of the growth interruption time between the e nd of QDs' growth and the start of the GaAs layer overgrowth makes these mo difications of the PL spectra with surface misorientation stronger and the efficiency of the PL higher. With the use of misoriented substrates, single sheet QD laser with threshold current density of 210 A/cm(2) at room tempe rature was realized. (C) 1999 Elsevier Science B.V. All rights reserved.