Highest density 1.3 μm InAs quantum dots covered with gradient composition InGaAs strain reduced layer grown with an As2 source using molecular beam epitaxy

We propose a GaAs-based 1.3 mu m InAs quantum dot (QD) structure for optical devices that uses dimeric arsenic (As-2) and a highly strained GaInAs cover layer. The characteristics of 1.3 mu m InAs QDs that employ AS(2) are different from those of QDs that use As-4. Our optimum structure exhibits the first room temperature emission of over 1.3 pin with a linewidth of 22 meV and a high density of over I X 1011 cm(-2) using only a cover layer. We were also able to achieve a very high density of 3.3 x 10(11) cm(-2) and a full width at half mazimum of 23 meV for a triple-stack structure within the critical thickness. This result is promising as regards achieving an optical device with QDs of over 1.3 pin on a GaAs substrate for use in fiber communications.