Solid-diffusion-facilitated cleaning of copper foil improves the quality of CVD graphene

Dinh Tuan Nguyen, Wan Yu Chiang, Yen Hsun Su, Mario Hofmann, Ya Ping Hsieh

Research output: Contribution to journalArticle

Abstract

The quality of CVD-grown graphene is limited by the parallel nucleation of grains from surface impurities which leads to increased grain boundary densities. Currently employed cleaning methods cannot completely remove surface impurities since impurity diffusion from the bulk to the surface occurs during growth. We here introduce a new method to remove impurities not only on the surface but also from the bulk. By employing a solid cap during annealing that acts as a sink for impurities and leads to an enhancement of copper purity throughout the catalyst thickness. The high efficiency of the solid-diffusion-based transport pathway results in a drastic decrease in the surface particle concentration in a relatively short time, as evident in AFM and SIMS characterization of copper foils. Graphene grown on those substrates displays enhanced grain sizes and room-temperature, large-area carrier mobilities in excess of 5000 cm2/Vs which emphasizes the suitability of our approach for future graphene applications.

Original languageEnglish
Article number257
JournalScientific reports
Volume9
Issue number1
DOIs
Publication statusPublished - 2019 Dec 1

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All Science Journal Classification (ASJC) codes

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