Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

DS: Fachverband Dünne Schichten

DS 33: New Twists for Nanoquakes on a Chip - Emerging Applications of Surface Acoustic Waves in Condensed Matter Physics (Focussed Session): Session II

DS 33.1: Vortrag

Donnerstag, 15. März 2018, 15:00–15:15, H 2032

Acousto-electric transport in epitaxial graphene coated by a ZnO piezoelectric film — •Yi-ting Liou, Alberto Hernández-mínguez, Jens Herfort, João marcelo Lopes, Abbes Tahraoui, and Paulo Santos — Paul-Drude-Institut, Berlin, Germany

We report on the transport of charge carriers in epitaxial graphene on SiC induced by surface acoustic waves (SAWs). SAWs are elastic vibrations propagating along a surface, which can be generated by applying a radio-frequency power to interdigital transducers (IDTs) deposited on piezoelectric materials. In this contribution, we report acousto-electric currents in epitaxial graphene covered by MgO and ZnO. The ZnO film provides a strong piezoelectric potential, which facilitates the acoustic transport in graphene using GHz SAWs. The 15-nm thick MgO layer is used as gate dielectric and also protects the graphene during the ZnO sputtering process. Raman spectra after the deposition of MgO and ZnO show no defect generated in graphene. In addition, the field-effect mobility at room temperature is about 2970 cm² V⁻¹ s⁻¹, which indicates that the electrical properties of graphene were preserved. The acousto-electric current was found to be of the order of 10 to 60 nA [1], which is up to 75 times larger than in a previous work using a 200 nm-thick SiO₂ layer instead of MgO [2]. Prospective work will include the investigation of acousto-electric transport while gate voltages are applied to further control the electrical properties of graphene.

[1] J. Phys. D: Appl. Phys. 50, 464008 (2017)

[2] Appl. Phys. Lett. 108, 193502 (2016)