Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 3: III-V semiconductors I
HL 3.12: Vortrag
Montag, 27. März 2006, 13:00–13:15, POT 51
Carrier transport by acoustic fields in InP-based structures — •Markus Beck1, Maurício M. de Lima1, Jörg Rudolph1, Richard Nötzel2, and Paulo V. Santos1 — 1Paul Drude Institut für Festkörperelektronik, Berlin, Germany — 2Technische Universiteit, Eindhoven, Netherlands
We investigate the modulation of the optical properties and the ambipolar transport of photogenerated electrons and holes by surface acoustic waves (SAWs) in InGaAsP structures. The generation of SAWs using interdigital transducers (IDTs) in InP-based materials is limited by the low piezoelectric coupling. We succeed to generate strong SAW fields by coating them with a piezoelectric ZnO film (typically, 0.5 µm-thick) deposited using a low temperature (<200∘C) process. The insertion loss of acoustic delay lines on ZnO-coated InP-substrates could be reduced to 10 dB. The photoluminescence intensity of InGaAsP structures with emission wavelength of 1470 nm at 5 K is drastically reduced under acoustic excitation. This effect is attributed to the spatial separation and transport of the photogenerated electrons and holes by the piezoelectric field, as previously observed for GaAs. The carriers are acoustically transported over distances on the order of 200 µm. The photoluminescence from the transported carrier can be retrieved by forcing their recombination in an area where the ZnO film has been removed. These results demonstrate that acoustic fields can be used to control carriers in InP-based structures operating at telecommunication wavelengths. (Supported by the EU-ePIXnet consortium)