Transmissible Plasma-Evolved Suspended Graphene for TEM Observation Window

Abstract

We show a technique to produce suspended graphene with a short processing time and very low temperature by employing a pulsed arc plasma. The catalytically active metal plasma (isolated ions and electrons of metal) is revealed to be transmissible through a suspended amorphous carbon (a-C) membrane, and the a-C evolves into highly graphitized C (sp2-C). The produced sp2-C is referred to as transmissible plasma-evolved graphene (TPEG). In this process, a pulsed arc plasma is generated from negatively biased metal electrodes, where each pulse lasts for a fraction of a second, and the catalytic activity of the plasma into the sample surface is tuned by both the applied bias voltage at cathode and the number of pulses. Furthermore, TPEG with nanoparticles and single-walled carbon nanotubes are successfully produced onto transmission electron microscopy (TEM) observation window by employing a dual-pulsed arc plasma source, indicating that this process is an efficient approach to fabricate their heterostructures, and ascertains that the TPEG can be utilized for the characterization of zero- and one-dimensional materials, such as graphene synthesized by chemical vapor deposition (CVD). In addition, even a-C on a polymer support is successfully transformed into graphene by the TPEG technique without sacrificing the polymer support, which confirmed that TPEG is formed near room temperature. This process is an avenue for the transformation of various amorphous materials into their crystalline structure, similar to the transformation of a-C into sp2-C.