Regensburg 2010 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 41: Quantum Dots and Wires: Preparation and Characterization II

HL 41.6: Talk

Wednesday, March 24, 2010, 12:15–12:30, H13

DLTS measurements on GaSb/GaAs quantum dots — •Annika Högner¹, Tobias Nowozin¹, Andreas Marent¹, Dieter Bimberg¹, Chi-Che Tseng², and Shih-Yen Lin³ — ¹Institut für Festkörperphysik, TU Berlin, Hardenbergstr. 36, 10623 Berlin — ²Institute of Photonics Technologies, NTHU, Taiwan — ³Institute of Optoelectronic Sciences, NTOU, Taiwan

Memory devices based on hole storage in self-organized quantum dots offer significant advantages with respect to storage time and scalability. Recently, we demonstrated a first prototype based on InAs/GaAs quantum dots at low temperatures [1]. To enable feasible storage times at room temperature the localisation energy of the quantum dots has to be increased by using other material systems. A first step in this direction is the use of GaSb quantum dots within a GaAs matrix.
We have characterized self-organized GaSb/GaAs quantum dots embedded into a n⁺p-diode structure. DLTS measurements on hole emission were conducted and yield a strong peak from which a mean emission energy of about 400 meV can be extracted. The reference sample without the quantum dots (containing only the wetting layer) shows no such peak.

A. Marent, T. Nowozin, J. Gelze, F. Luckert, and D. Bimberg, "Hole-based memory operation in an InAs/GaAs heterostructure", Appl. Phys. Lett. (in press).