Münster 1997 – scientific programme
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HL: Halbleiterphysik
HL 22: Poster II
HL 22.104: Poster
Tuesday, March 18, 1997, 15:30–18:30, Z
Optical characterisation of self organised InGaAs / InP heterodots — •C. Guasch1, C M. Sotomayor Torres1, J. Ahopelto2, H. Lipsanen3, M. Sopanen3, I. Gontijo4, and G. S. Buller4 — 1Institut fur Materialwissenschaften, Universitat Wuppertal, Fuhlrottstrasse 10, D-42097 Wuppertal, Germany — 2VTT Electronics, Otakaari 7 B, FIN-02150 Espoo, Finland — 3Optoelectronics Laboratory, Helsinki University of Technology, Otakaari 1 M, FIN-02150 Espoo, Finland — 4Heriot-Watt University, Department of Physics, Edinburgh EH 14 4AS, U.K.
Direct growth of semiconductor quantum dot structures can now be achieved in standard growth systems by using lattice mismatch induced three dimensional growth. Here we present the optical properties of heterodots which are formed by selective growth of a thin InGaAs layer on top of nanoscale InP islands. The photoluminescence spectrum from these InGaAs heterodots exhibits a peak at 1.387 eV with a full width at half maximum of 12 meV. However, time-resolved photoluminescence spectra exhibit very efficient relaxation processes from the wetting layer and from the surrounding GaAs to the InGaAs layer. Finally, recombinations paths occuring in this system are identified according to a proposed schematic band diagram