Acousto-electric modulation
of few-layer epitaxial graphene

Host: Paul-Drude Institut für Festkörperelektronik (PDI)
Supervisor: P. V. Santos (PDI), Co-supervisor: W. van der Wiel (TWENTE)

Berlin

Yi-Ting Liou


Yi-Ting Liou’s research interest contains two-dimensional materials and electronics. She studied Materials Science and Engineering in National Taiwan University, and obtained her Bachelor and Master Degree in 2012 and 2014, respectively. During her Master’s study she worked on graphene-based devices, such as photovoltaics and phototransistors. In addition to device fabrication, she also has experiences on graphene growth and characterization.


Objectives


This Project aims to exploit super high-frequency (SHF, >3 GHz) SAWs for carrier transport and band-structure modulation of epitaxial graphene (epiG) on SiC. The ESR will synthesise epiG and study transport properties under SAW with wavelengths comparable to the carrier mean free path (≤100 nm) aiming at mobility control and possible detection of phonon-mediated superconductivity. Strong SAW fields will be obtained by coupling epiG to phononic crystals.

The activities will include (i) epiG synthesis by surface graphitization of SiC, (ii) fabrication of SHF IDTs by nanoimprint lithography (secondment at NTD/TWENTE) and e-beam lithography (secondment at CHALMERS), (iii) Raman and magneto-transport spectroscopy studies (secondment at LEEDS) under short-period SAWs (see also WP3-5), (iv) fabrication and characterisation of phononic crystals on epiG (secondment at QUEENS). Theoretical support and training will be provided by CSIC/UCM.

Expected Results


Demonstration of carrier control and transport in epiG by SHF SAWs, aiming at acoustic switches and attenuators and analogues to optical devices (e.g. electron super-collimators and lenses). The multidisciplinary training will include: synthesis of epiG on SiC, characterization techniques (Raman spectroscopy, AFM, Hall measurements), cleanroom techniques (photolithography, nanoimprint lithography, e-beam lithography, etching, sputtering of piezoelectric layers), measurement techniques for SAW devices (interferometry, magnetotransport, spectroscopy), design of phononic-crystals and characterization, as well as theoretical training.

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