InGaAs quantum dots grown on B-type high index GaAs substrates: surface morphologies and optical properties

摘要

We systematically investigated the correlation between morphological and optical properties of InGaAs self-assembled quantum dots (QDs) grown by solid-source molecular beam epitaxy on GaAs (n11) B (n = 9, 8, 7, 5, 3, 2) substrates. Remarkably, all InGaAs QDs on GaAs( n11) B under investigation show optical properties superior to those for ones on GaAs( 100) as regards the photoluminescence (PL) linewidth and intensity. The morphology for growth of InGaAs QDs on GaAs ( n11) B, where n = 9, 8, 7, 5, is observed to have a rounded shape with a higher degree of lateral ordering than that on GaAs( 100). The optical property and the lateral ordering are best for QDs grown on a ( 511) B substrate surface, giving a strong correlation between lateral ordering and PL optical quality. Our results demonstrate the potential for high quality InGaAs QDs on GaAs( n11) B for optoelectronic applications.