Photoluminescence study of the 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 (GSMBE) 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