Nano Res. 2011, 4(3): 315–321 315 Catalyst-Free Growth of Nanographene Films on Various Substrates Lianchang Zhang 1 , Zhiwen Shi 1, 2 , Yi Wang 1, 2 , Rong Yang 1 , Dongxia Shi 1 , and Guangyu Zhang 1 (  ) 1 Nanoscale Physics and Device Lab, Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China 2 Surface Physics Lab, Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China Received: 3 November 2010 / Revised: 22 November 2010 / Accepted: 23 November 2010 © Tsinghua University Press and Springer-Verlag Berlin Heidelberg 2010 ABSTRACT We have developed a new method to grow uniform graphene films directly on various substrates, such as insulators, semiconductors, and even metals, without using any catalyst. The growth was carried out using a remote plasma enhancement chemical vapor deposition (r-PECVD) system at relatively low temperatures, enabling the deposition of graphene films up to 4-inch wafer scale. Scanning tunneling microscopy (STM) confirmed that the films are made up of nanocrystalline graphene particles of tens of nanometers in lateral size. The growth mechanism for the nanographene is analogous to that for diamond grown by PECVD methods, in spite of sp 2 carbon atoms being formed in the case of graphene rather than sp 3 carbon atoms as in diamond. This growth approach is simple, low-cost, and scalable, and might have potential applications in fields such as thin film resistors, gas sensors, electrode materials, and transparent conductive films. KEYWORDS Nanographene, catalyst-free, plasma enhancement chemical vapor deposition (PECVD), transparent and conductive film Graphene has attracted much attention owing to its unique structure [1, 2], interesting properties [1, 3–5], and promising device applications [1, 6, 7]. Among many studies on graphene, growth of graphene has been intensively explored recently as it provides potential routes for scaled-up applications. Several techniques have been developed: Epitaxial growth [8–14] requires quite expensive single crystalline substrates, and thus, has limited applications; chemical vapor deposition (CVD) on various catalytic metal films [15–18] is low-cost, but it requires catalyst films, and post-transfer [19] or additional catalyst removal techniques [20] are necessary to support the graphene on a substrate. Here we report for the first time a catalyst-free graphene growth approach. Without using any catalyst, nanocrystalline graphene with a size about tens of nanometers has been directly grown on various substrates at a relatively low temperature of 550 ° C. The sp 2 bonded honeycomb carbon lattice structure of the as-grown materials was confirmed by Raman spectroscopy, X-ray photoemission spectros- copy (XPS), and scanning tunneling microscopy (STM). Conductivity and transparency properties of the nanographene film were also studied. This simple, Nano Res. 2011, 4(3): 315–321 ISSN 1998-0124 DOI 10.1007/s12274-010-0086-5 CN 11-5974/O4 Research Article Address correspondence to gyzhang@aphy.iphy.ac.cn