Understanding and Controlling the Substrate Effect on Graphene Electron-transfer Chemistry via Reactivity Imprint Lithography
- Category: Materials, Nanotechnology
- Tags: michael strano, qing hua wang
Graphene has exceptional electronic, optical, mechanical, and thermal properties, which provide it with great potential for use in electronic, optoelectronic and sensing applications[1]. The chemical functionalization of graphene has been investigated with a view to controlling its electronic properties and interactions with other materials[2]. Covalent modification of graphene by organic diazonium salts has been used to achieve these goals, but because graphene comprises only a single atomic layer, it is strongly influenced by the underlying substrate. In our work here[3], we show a stark difference in the rate of electron-transfer reactions with organic diazonium salts for monolayer graphene supported on a variety of substrates. Reactions proceed rapidly for graphene supported on SiO2 and Al2O3 (sapphire), but negligibly on alkyl-terminated and hexagonal boron nitride (hBN) surfaces, as shown by Raman spectroscopy. We also develop a model of reactivity based on substrate-induced electron–hole puddles in graphene and achieve spatial patterning of chemical reactions in graphene by patterning the substrate.
- A. K. Geim1 and K. S. Novoselov, “The rise of graphene,” Nature Materials, vol. 6, pp. 183-191, Mar. 2007. [↩]
- G. L. C. Paulus, Q. H. Wang, and M. S. Strano, “Covalent Electron Transfer Chemistry of Graphene with Diazonium Salts,” Accounts of Chemical Research, vol. 46, pp. 160-170, Sep. 2012. [↩]
- Q. H. Wang, Z. Jin, K. K. Kim, A. J. Hilmer, G. L. C. Paulus, C.-J. Shih, M.-H. Ham, J. D. Sanchez-Yamagishi, K. Watanabe, T. Taniguchi, J. Kong, P. Jarillo-Herrero, and M. S. Strano, “Understanding and controlling the substrate effect on graphene electron-transfer chemistry via reactivity imprint lithography,” Nature Chemistry, vol. 4, pp. 724-732, Aug. 2012. [↩]