Improved optical properties of InAs quantum dots grown with an As_2 source using molecular beam epitaxy

摘要

We demonstrate the effects of using an As_2 source to fabricate self-organized InAs/GaAs quantum dot (QD) structures. QDs grown with an As_2 source have narrower photoluminescence (PL) linewidths and higher PL intensities than those grown with an As_4 source at high growth rates. The density of QDs grown with an As_2 source is smaller, and the dot size larger than those of QDs grown with an As_4 source. The coalescence of QDs is reduced under an As_2 source, resulting in improved optical properties. These results are thought to result from the difference in the surface migration of In atoms and the surface structures under As_2 and As_4 sources.