Regensburg 2010 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 64: Quantum Dots and Wires: Optical Properties VI
HL 64.6: Talk
Friday, March 26, 2010, 11:45–12:00, H14
Optical properties of GaAs quantum dots fabricated by filling of self-assembled nanoholes — •Christian Heyn1, Andrea Stemmann1, Tim Köppen1, Christian Strelow1, Tobias Kipp1, Matthias Grave1, Matthias Klingbeil1, Stefan Mendach1, Andreas Schramm2, and Wolfgang Hansen1 — 1Institut für Angewandte Physik,Jungiusstr 11, 20355 Hamburg — 2Optoelectronics Research Centre, Tampere University of Technology, Finnland
Local droplet etching (LDE) is a very powerful technique which allows the self-assembled patterning of GaAs or AlGaAs surfaces without any lithographic steps. The LDE process starts with the generation of Ga, Al, or In droplets on the surface. Using appropriate process temperatures, deep nanoholes are drilled beneath the liquid droplets into the substrate. The method was introduced by Wang et al. [1] for etching of GaAs surfaces with Ga droplets. We have expanded the range of materials [2] and studied the time evolution of the LDE process [3]. By filling of nanoholes in AlGaAs with GaAs, we have fabricated GaAs quantum dots (QDs).[4] Dependent on the process parameters, ensembles of these LDE QDs show either broadband optical emission or very sharp lines up to room temperature. Furthermore, the optical fine-structure of single LDE QDs is studied.
[1] Zh. M. Wang et al., Appl. Phys. Lett. 90, 113120 (2007).
[2] A. Stemmann et al., Appl. Phys. Lett. 93, 123108 (2008).
[3] Ch. Heyn et al., Appl. Phys. Lett. 95, 173110 (2009)
[4] Ch. Heyn et al., Appl. Phys. Lett. 94, 183113 (2009).