Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 14: Focus Session: Site-selective Growth of single Quantum Dots

HL 14.5: Topical Talk

Montag, 26. März 2012, 17:15–17:45, ER 164

Pre-patterned silicon and GaAs substrates for the growth of III-V nanostructures: morphological and optical properties — •Mohamed Benyoucef, Muhammad Usman, Tariq Al Zoubi, Aleksandar Gushterov, Tino Pfau, and Johann Peter Reithmaier — Institute of Nanostructure Technologies and Analytics (INA), Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, Heinrich-Plett-Strasse 40, D-34132 Kassel, Germany

Light emission from direct growth of III-V quantum dots (QDs) on silicon (Si) is a future dream. However, the presence of high-density threading dislocations due to the lattice mismatch and the formation of antiphase boundaries due to the polar/non polar nature destroy the light emission. Growth on pre-patterned substrates could results in reducing or eliminating such defects due to size effect.

In this talk, we report on growth of site-controlled InAs QDs on pre-patterned GaAs and Si substrates based on dry and wet-chemical etching. In the first part, a review on the recent work on pre-patterned GaAs will be provided. Results of an optimized wet-chemically etching holes and a special MBE growth stack technique will be presented. GaAs based single QDs emissions is probed by micro-PL and reveals clear spectra with single lines. In the second part, we present the results of the optimized electron beam lithography and dry etching processes for the patterning of Si substrates. The MBE growth of QDs on patterned Si surface with highly selective formation of localized InAs nanostructures in patterned holes with 1 µm period will be discussed.