Argon-plasma-induced InAs/InGaAs/InP quantum dot intermixing.

We report the first study of argon (Ar)-plasma-enhanced intermixing of InAs/InGaAs/InP self-assembled quantum dots (QDs) in an inductively coupled plasma reactive ion etch system. The Ar-plasma exposure creates point defects, which propagate into the QD structure and enhance the intermixing between the QDs and their barrier layers, hence tuning the energy bandgap of the QDs. By optimizing the plasma exposure time and the annealing temperature, we observe (i) a blueshift of 160 nm and an increase in the photoluminescence (PL) intensity of the QD samples immediately after Ar-plasma exposure for 90 s, and (ii) a further increase in the blueshift of 330 nm, accompanied by 2.

Formation of mid-infrared emissive InAs quantum dots on a graded InxGa1-xAs/InP matrix with a more uniform size and higher density under safer growth conditions.

InAs mid-infrared emissive quantum dots (QDs) grown on a graded InxGa1-xAs/InP matrix with more uniform size and higher dot density have been successfully prepared by low pressure metal organic chemical vapour deposition (LP-MOCVD) under safer growth conditions. Low toxic tertiarybutylarsine and tertiarybutylphosphine sources were used to replace the high toxic arsine and phosphine in the MOCVD growth. To improve the process safety further, inertial N2 instead of the normally used explosive H2 was used as the carrier gas.