Yongqiang Wang1
Los Alamos National Laboratory1
Yongqiang Wang1
Los Alamos National Laboratory1
<b>Ion Beam Synthesis of Layer-Tunable and Transfer-Free Graphene on Arbitrary Substrates Towards Versatile Applications</b><br/> <br/><i>G. Wang<sup>1</sup>, X.Q. Feng<sup>1</sup>, J.K. Baldwin<sup>2</sup>, Z.F. Di<sup>3</sup>, and <u>Y.Q. Wang<sup>2</sup></u><sup>,4</sup></i><br/><sup>1</sup>Department of Microelectronic Science and Engineering, Ningbo University, Ningbo, China<br/><sup>2</sup>Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico, USA<br/><sup>3</sup>State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Shanghai, China.<br/><sup>4</sup>Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico, USA.<br/> <br/>Direct synthesis of transfer-free and layer-tunable graphene on an arbitrary substrate is highly valued for multiple daily life applications. Here, through employing ion implantation into a Cu/Ni dual metal smart Janus substrate, a well-controlled number of layers of graphene, primarily monolayer and bilayer, can be precisely synthesized <i>via</i> the equivalent fluence of the implanted carbon (C) ions. More importantly, the top Cu film, behaving like an excellent C-diffusion barrier (due to its limited solubility of C), gradually inter-diffuses into the bottom Ni layer during the post-implantation thermal annealing and leads to the implanted C atoms being regularly expelled toward the moving-in interface of the newly formed Cu-Ni alloy and eventually transformed into graphene structure on the substrate. The elemental diffusion during the graphene synthesis is confirmed by secondary ion mass spectrometry (SIMS). It is discovered that all of the implanted C atoms were expelled towards the substrate surface to form transfer-free graphene on arbitrary substrates as characterized by Raman spectroscopy, atomic force microscopy and select area electron diffractions. We demonstrated that the graphene films synthesized on such objective substrates as SiO<sub>2</sub>, glass, and Si exhibited excellent properties and device performance as field-effect transistors, heating devices and near-infrared photodetectors without needing any post-transfer process. Our study affords a multifaceted plan for graphene on arbitrary substrates, with well-controlled layer and transfer-free versatile device manufacturing, expediting their applications in many fields.