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HL: Fachverband Halbleiterphysik
HL 7: Single Photon Sources and Qbits
HL 7.5: Vortrag
Montag, 14. März 2011, 12:00–12:15, FOE Anorg
Spectroscopy of electrically controlled intentionally positioned and shape engineered single InAs quantum dots — Minisha Mehta1, Dirk Reuter2, Andreas D. Wieck2, Stefan Michaelis de Vasconcellos1, Artur Zrenner1, and •Cedrik Meier1 — 1Physics Department ,Paderborn, Germany — 2Applied Solid State Physics, Ruhr-University of Bochum, Bochum, Germany
Precise control of position and electronic/excitonic states of self-assembled quantum dots (QDs) might open exciting options towards single QD devices. We report the realization of an electrically driven single photon source by integrating an epitaxial InAs QD within a micron sized GaAs based p-i-n junction device. Two different growth techniques were employed: QD position control was achieved using site-selective growth of InAs QDs on focused ion beam (FIB) patterned GaAs surfaces. Engineering of electronic/excitonic states was achieved utilizing the growth of flushed InAs QDs on smooth GaAs surface via MBE. After the complete growth of p-i-n diode-like structure, FIB patterning and etching was used to fabricate LEDs having active area of 2×2 µm2. Then, carrier injection and subsequent radiative recombination from site-selective and flushed InAs QDs was investigated individually. Few or single dots are expected to be electrically addressed in these devices. The result from micro-electroluminescence (EL) shows single dot characteristics from both devices. The EL spectra consist of sharp emission lines and their dependence on injection current is presented. Thus, these results suggest a promising pathway for quantum devices [1]. [1] M. Mehta et al., Appl. Phys. Lett. 97, 143101 (2010).