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Controlled Synthesis of InAs Wires, Dot and Twin-Dot Array configurations by Cleaved Edge Overgrowth. E. Uccelli, M. Bichler, S. Nürnberger, G. Abstreiter, A. Fontcuberta i Morral Nanotechnology 19 , 2008. What is it all about?.
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Controlled Synthesis of InAs Wires, Dot and Twin-Dot Array configurations by Cleaved Edge Overgrowth E. Uccelli, M. Bichler, S. Nürnberger, G. Abstreiter, A. Fontcuberta i Morral Nanotechnology19, 2008
What is it all about? Control of size and thereby emission properties of QDs is possible but control of position is more challenging Uccelli, Bichler, Nürnberger, Abstreiter and Fontcuberta i Morral In situ cleaved edge overgrowth to control the nucleation of InAs QDs
Cleaved Edge Overgrowth- Fabrication I Left: L. Pfeiffer et al., Appl. Phys. Lett.56, 1697 (1990)Right: G. Schedelbeck et al., Science 278, 1792 (1997)
Growth of InAs Structures on Cleaved GaAs/AlAs- Fabrication II Stranski-Krastanov growth mode
Phenomenological Growth Models γs = γsf + γf cosφ Layer-by-layer Frank-van der Merve Layer-plus-island Stranski-Krastanov Island Vollmer-Weber γs ≥ γsf + γf + CkBT ln(p0/p) γs < γsf + γf + CkBT ln(p0/p)
Mechanism for Growth 1 ML = 2.83 Å
Conclusion • Atomic precison of MBE used for positioning of QDs and other structures • Technique seems limited to simple geometries because of the use of cleavage planes • Small window for preferential growth on AlAs but it is there! Questions?