Self-organized InAs/GaAs quantum dots grown by gas source molecular beam epitaxy

Self-organized InAs quantum dots (QDs) grown on both (100) exact and (100) misoriented 7° toward (110) GaAs substrates using gas source molecular beam epitaxy with V/III ratio ranging from 1.1 to 20 have been studied by photoluminescence (PL) measurements from 8.5 to 300 K. The QD structures grown on the misoriented substrates show a better uniformity than those grown on the exact substrates at the same growth conditions. Effects of AsH3 flow rate on the PL intensity, peak energy, and linewidth for QDs grown on both types of substrates are presented. Basically, higher AsH3 flow rate gives higher PL intensity at 8.5 K. At room temperature (300 K), on the contrary, lower AsH3 flow rate results in higher PL intensity. The study of thermal quenching energy reveals that the larger the dot size the better the PL intensity at 300 K.