Baik, Min Kyhm, Ji-hoon Kang, Hang-Kyu Jeong, Kwang-Sik Kim, Jong Su Cho, Mann-Ho Song, Jin Dong 2024-01-19T15:03:06Z 2024-01-19T15:03:06Z 2021-09-05 2021-04 2045-2322 https://pubs.kist.re.kr/handle/201004/117207 We report the growth mechanism and optical characteristics of type-II band-aligned GaSb quantum dots (QDs) grown on GaAs using a droplet epitaxy-driven nanowire formation mechanism with molecular beam epitaxy. Using transmission electron microscopy and scanning electron microscopy images, we confirmed that the QDs, which comprised zinc-blende crystal structures with hexagonal shapes, were successfully grown through the formation of a nanowire from a Ga droplet, with reduced strain between GaAs and GaSb. Photoluminescence (PL) peaks of GaSb capped by a GaAs layer were observed at 1.11 eV, 1.26 eV, and 1.47 eV, assigned to the QDs, a wetting-like layer (WLL), and bulk GaAs, respectively, at the measurement temperature of 14 K and excitation laser power of 30 mW. The integrated PL intensity of the QDs was significantly stronger than that of the WLL, which indicated well-grown GaSb QDs on GaAs and the generation of an interlayer exciton, as shown in the power- and temperature-dependent PL spectra, respectively. In addition, time-resolved PL data showed that the GaSb QD and GaAs layers formed a self-aligned type-II band alignment; the temperature-dependent PL data exhibited a high equivalent internal quantum efficiency of 15 +/- 0.2%. English Nature Publishing Group Optical characteristics of type-II hexagonal-shaped GaSb quantum dots on GaAs synthesized using nanowire self-growth mechanism from Ga metal droplet Article 10.1038/s41598-021-87321-9 1 Scientific Reports, v.11, no.1 Scientific Reports 11 1 Y scie scopus 000639562100019 2-s2.0-85104093143 Multidisciplinary Sciences Science & Technology - Other Topics Article VERTICAL TRANSPORT ELECTRON STRAIN DYNAMICS type-II GaSb Nanowire droplet