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HL: Halbleiterphysik

HL 3: Quantenpunkte und -dr
ähte: Herstellung und Charakterisierung

HL 3.5: Vortrag

Montag, 8. März 2004, 11:15–11:30, H17

InAs quantum dots grown on the GaAs(2, 5, 11)A and B surfaces: a STM and PL study — •Yevgeniy Temko, Takayuki Suzuki, Ming Chun Xu und Karl Jacobi — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin

InAs quantum dots (QDs) were grown by molecular beam epitaxy on GaAs(2, 5, 11)A [1] and B surfaces. By atomically resolved in situ scanning tunnelling microscopy we determine the main bounding facets on the QDs. On both substrates the QDs are faceted by 110-, 111-surfaces and a rounded region formed by vicinal (001) stacking. The latter becomes faceted on large islands. There is no mirror symmetry on the QDs in agreement with substrate symmetry. Besides this similarity there are also differences: On the (2, 5, 11)A substrate the QDs shape is elongated whereas those on the GaAs(-2,-5,-11)B are rather rounded similar to the InAs QDs grown on GaAs(113)A and B [2,3,4]. The size distribution of the islands on the B face is much sharper than on the A face which is also confirmed by the low-temperature photoluminescence measurements.

[1] L.Geelhaar, J.Marquez, P.Kratzer, and K.Jacobi, Phys. Rev. Lett. 86, 3815 (2001)

[2] T.Suzuki, Y.Temko, and K.Jacobi, Appl. Phys. Lett. 80, 4744 (2002)

[3] Y.Temko, T.Suzuki, and K.Jacobi, Appl. Phys. Lett. 82, 2142 (2003)

[4] Y.Temko, T.Suzuki, M.C.Xu, and K.Jacobi, Appl. Phys. Lett. 83, 3680 (2003)