| Autor: |
Garcia, A., Mateo, C. M., Defensor, M., Salvador, A., Hui, H. K., Boothroyd, C. B., Philpott, E. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; Oct2007, Vol. 102 Issue 7, p073526, 4p, 1 Color Photograph, 4 Graphs |
| Abstrakt: |
We report the effects of variations in As4 growth flux on the evolution of molecular beam epitaxy grown InAs quantum dots (QDs) and their structures and optical properties. For InAs QDs grown under As-stable conditions, evaluated through photoluminescence and atomic force microscopy (AFM) measurements, it is evident that QD size increases with As4 pressure along with improvement in size uniformity. Furthermore, transmission electron microscopy measurements for InAs layers of critical thicknesses (∼1.7 ML) showed decreasing QD density with increasing As4 pressure accompanied by a strong reduction in photoluminescence (PL) integral intensity. These show that high As4 fluxes suppress InAs QD formation while the decreasing PL intensity seems to indicate cluster formation that features nonradiative recombination. AFM measurements show larger and denser QDs for samples grown at higher As4 pressures. These are explained on the basis of adatom condensation during surface cooling and the influence of As4 pressure on indium incorporation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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