Regensburg 2019 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 22: Plasmonics I (joint session O/CPP)

CPP 22.5: Vortrag

Dienstag, 2. April 2019, 11:30–11:45, H8

Electroluminescence from transparent graphene nanojunctions — •Christian Ott, Martin Hauck, Sascha Korn, and Heiko B. Weber — Lehrstuhl für Angewandte Physik, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstr. 7/Bau A3, D-91058 Erlangen, Germany

Electroluminescence (EL) emitted from metal-metal tunnel junctions has already been observed in STM experiments in the late 80s [1], nevertheless its origin is still under scientific discussion and is usually attributed either to plasmonic modes triggered by the granular nature of current [2] or to blackbody-like radiation of the injected hot electrons [3]. We report on EL emitted from graphene-graphene nanojunctions (GNJ) fabricated from epitaxial graphene on silicon carbide [4]. In stark contrast to STM experiments, GNJs provide a flat, accessible and transparent geometry, allowing an unobscured optical and electron-microscopic access. The observed EL shows a blackbody like spectrum with surprisingly high apparent temperatures well above the damage threshold of the material. Our findings are critically discussed in terms of differences and similarities to other reported experiments (especially STM) to highlight their contribution to the understanding of an elementary process of light-matter interaction.

[1] Schlittler et al., Z. Phys. B. 72, 497 - 501 (1988) [2] Peters et al., PRL 119, 066803 (2017) [3] Downes et al., Applied Physics Letters 81, 7 (2002) [4] Ullmann et al., Nano Letters 14, 5 (2015)