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.
© 2015 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letter, 106(10), 103104, and may be found at: 10.1063/1.4914895.
Ji, Hai-Ming; Liang, Baolai; Simmonds, Paul J.; Juang, Bor-Chau; Yang, Tao; 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 Letter, 106(10), 103104-1 - 103104-5.