Self-assembled InAs quantum dots on GaSb/GaAs(0 0 1) layers by molecular beam epitaxy

Effect of antimony on the density of InAs/Sb:GaAs(100) quantum dots grown by metalorganic chemical-vapor deposition

“…The microscopic mechanism of surfactant-mediated growth is still under debate, but the most generally reported effect of antimony surfactant species is to lower the surface energy and to drive the growth in a diffusion-limited regime, as well as to segregate to the growth front. In particular, the increase of the dot density was reported for Ge/Sb:Si QDs [6] as well as for InAs/Sb:GaAs QDs, either grown by MBE [7] or grown by MOCVD [8]. However, the effect of Sb on the photoluminescence (PL) characteristics at RT was not discussed.…”

Self-formation of ultrahigh-density (1012 cm−2) InAs quantum dots on InAsSb/GaAs(001) and their photoluminescence properties

“…Despite the extremely high QD density, the formation of coalesced giant dots was suppressed by the Sb surfactant effect. 17) To obtain a better understanding of high-density nucleation, the InAsSb WL surface structure was imaged by AFM. Figures 3(a) and 3(b) show AFM images of 1.25 ML InAs WLs grown on GaAs buffer layers at 500 and 460°C, respectively.…”

“…20,21) Therefore, the InAsSb WL structure enhances the in-plane density of 3D islands. Furthermore, segregated Sb surface atoms suppress the coalescence of neighboring 3D islands, 17) and the small islands prevent ripening. 15) Therefore, the ultrahigh-density InAs QDs were derived from multiple effects.…”

Recent progress on quantum dot solar cells: a review

“…For the forward bias condition, the PL peak shifted toward the low energy side because the enhanced coupling among QDs caused the electron to relax at much lower ground energy states in the QDs with large size. 22,23,55 Meanwhile, the reverse bias was also found to shift the PL peak energy to long wavelength side. This was partially attributed to the strong Stark effect and partially to the fast electron escape rate, which greatly suppressed the high energy interband transition in the QDs.…”