Ji, Hai-ming and Liang, Baolai and Simmonds, Paul J. and Juang, Bor-chau and Yang, Tao and Young, Robert J. and Huffaker, Diana L. (2015) Hybrid type-I InAs/GaAs and type-II GaSb/GaAs quantum dot structure with enhanced photoluminescence. Applied Physics Letters, 106 (10): 103104. ISSN 0003-6951
Abstract
We investigate the photoluminescence (PL) properties of a hybrid type-I InAs/GaAs and type-II GaSb/GaAs quantum dot (QD) structure grown in a GaAs matrix by molecular beam epitaxy. This hybrid QD structure exhibits more intense PL with a broader spectral range, compared with control samples that contain only InAs or GaSb QDs. This enhanced PL performance is attributed to additional electron and hole injection from the type-I InAs QDs into the adjacent type-II GaSb QDs. We confirm this mechanism using time-resolved and power-dependent PL. These hybrid QD structures show potential for high efficiency QD solar cell applications.