Regensburg 2004 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
HL: Halbleiterphysik
HL 42: Quantenpunkte und -dr
ähte: Optische Eigenschaften II
HL 42.1: Talk
Thursday, March 11, 2004, 15:15–15:30, H13
Investigations of electrically contacted single quantum dots — •U. Scholz1, R. Schmidt1, M. Vitzethum1, R. Fix1, S. Malzer1, C. Metzner1, P. Kailuweit2, D. Reuter2, A. Wieck2, M.C. Hübner3, S. Stufler3, A. Zrenner3, and G.H. Döhler1 — 1Technische Physik I, Universität Erlangen-Nürnberg — 2Angewandte Festkörperphysik, Ruhr-Universität Bochum — 3AG Nanostructure Optoelectronics, Universität Paderborn
We investigate single quantum dots (QDs) embedded in the intrinsic region of a micro-LED. The active area of the LED is defined by the intersection of a p- and a n-doped stripe. The bottom stripe is defined by focussed ion beam implantation (FIB) which easily provides the necessary lateral resolution of a few 100 nm. The perpendicular top stripe is fabricated by wet chemical etching to µm or sub-µm width. As the dot densities of our samples are typically less than 109cm−2, the active area of the LED, on the average, contains one QD. We find single QD spectra in EL measurements. Extremely sharp recombination lines are observed up to the third excited state (f-shell). Within the different shells several emission peaks are visible, which can be attributed to differently charged excitons. All the lines show a pronounced red shift with increasing bias voltage due to the Stark effect. Polarisation resolved measurements suggest for the p-shell an anisotropy of the lateral confinement potential. We will also discuss voltage dependent photo current measurements and the application for a single photon turnstile device.