Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 7: Quantum dots: Optical properties I

HL 7.11: Vortrag

Montag, 23. März 2009, 16:30–16:45, BEY 118

Phonon replica of a single electrically pumped InAs/GaAs quantum dot from large diodes without current constriction — •Erik Stock¹, Andreas Baumgartner², Till Warming¹, Amalia Patane², Laurence Eaves², Mohamed Henini², and Dieter Bimberg¹ — ¹Institut für Festkörperphysik, Hardenbergstr. 36, 10623 Berlin, D — ²School of Physics and Astronomy, University of Nottingham NG7 2RD, UK

Electrical pumping of a single self organized quantum dots (QD) is essential for the fabrication of semiconductor based single photon and entangled photon pair sources. By controlling the applied bias we are able to pump a single quantum dot in a pin diode with a diameter of 200 µm containing a large number (≈10⁷) of InAs/GaAs QDs. No current constriction or shadow mask were necessary to observe single well resolved (< 0.2 meV) lines in the electroluminescence. This demonstrates the high carrier capture efficiency of a single QD.

We measure high resolution EL spectra, taken with large dynamic range. The observed emission line exhibits a broadening consistent with theoretically modelled acoustic phonon scattering. 36 and 39 meV below the emission line we observe a triangular shaped emission as it has been predicted theoretically for the optical phonon scattering [2]. These results show, how low-dimensional lattice vibrations couple to a single QD, which will be important for future applications. We acknowledge the SfB 787, NATO SfP 982735 and EPSRC, UK.

[1]L. Turyanska et al., Appl. Phys. Lett 89, 092106 (2006) [2]E. A. Muljarov, and R. Zimmermann, Phys. Rev. Lett. 98, 187401 (2007).