Regensburg 2022 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 38: 2D Materials 9 (joint session HL/CPP/DS)
CPP 38.1: Talk
Thursday, September 8, 2022, 11:15–11:30, H36
Generating extreme electric fields in 2D materials by dual ionic gating — •Benjamin Isaac Weintrub1, Yu-Ling Hsieh1,2, Jan N. Kirchhof1, and Kirill I. Bolotin1 — 1Department of Physics, Freie Universität Berlin, Berlin, Germany — 2Department of Mechanical Engineering, National Central University, Taoyuan City, Taiwan
We demonstrate a new type of dual gate transistor to induce record electric fields through two-dimensional materials (2DMs). At the heart of this device is a 2DM suspended between two volumes of ionic liquid (IL) with independently controlled potentials. The potential difference between the ILs falls across an ultrathin layer consisting of the 2DM and the electrical double layers above and below it, thereby producing an intense electric field across the 2DM. We determine the field strength via i) electrical transport measurements and ii) direct measurements of electrochemical potentials of the ILs using semiconducting 2DM, WSe2. The field strength across a bilayer WSe2 sample reaches ~2.5 V/nm, the largest static electric field through the bulk of any electronic device to date. Additionally, we create electric fields strong enough to close the bandgap of 3-layer and 4-layer WSe2 (~1.4 V/nm and ~0.9 V/nm respectively). Our approach grants access to previously-inaccessible phenomena occurring in ultrastrong electric fields.