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HL: Halbleiterphysik

HL 7: Poster I

HL 7.77: Poster

Monday, March 26, 2001, 10:30–19:00, Rang S\ 3

Study of carrier dynamics in double hetero p-i-n structures with self-assembled InAs quantum dots. — •V. Khorenko¹, M. Schardt¹, H. Plagwitz¹, S. Malzer¹, G. Döhler¹, C. Bock² und K.H. Schmidt² — ¹Institut für Technische Physik, Universität Erlangen-Nürnberg, Erwin-Rommel-Str. 1, D-91058 Erlangen — ²Lehrstuhl für Werkstoffe der Elektrotechnik, Ruhr-Universität Bochum, Universitätsstr. 150/IC2, D-44780 Bochum

The investigation of carrier injection in quantum dots (QDs) is of considerable interest due to the importance in low-dimensional physics and their application in optoelectronic devices. We have performed combined optical and electrical measurements to determine the energy levels, transition rules, relaxation and recombination kinetics, and Coulomb effects in InAs QDs embedded in double hetero (DH) p-i-n structures. Low temperature electroluminescence (EL) spectra have shown that the position of QD layer inside the intrinsic region (central, closer to the n- or p-layer) changes the (tunneling) injection efficiency for electrons or holes, respectively. As a consequence, EL of neutral or (either positively or negatively) charged dots can be observed. Efficiency, energy shift, and broadening of the spectra are investigated as a function of injection density (foreward current). The observed features can be compared with the theoretically expected (charged) exciton transitions of a (increasingly filled) dot ensemble.