MBE growth of InAs self-assembled quantum dots embedded in GaNAs strain-compensating layers

Abstract

We fabricated self-assembled InAs quantum dots (QDs) embedded with a combined set of a GaNAs strain-compensating layer (SCL) and an InGaAs strain-reducing layer (SRL) by using atomic hydrogen-assisted molecular beam epitaxy (H-MBE) with a RF plasma nitrogen source. By inserting an InGaAs SRL between the InAs QD layer and GaNAs SCL, we were able to achieve a significant improvement of optical properties. A 1.3 μ m -range photoluminescence (PL) emission was clearly obtained at 300 K from QDs embedded in a 5 nm-thick In 0.15Ga 0.85As SRL followed by a 20 nm-thick GaN 0.008As 0.992 SCL. Further, PL emission from the first excited state of QDs was also observed under a high excitation intensity of ∼ 20.0 W / cm 2 .