Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

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)