Mechanical properties of maze-like carbon nanowalls synthesized by the radial injection plasma enhanced chemical vapor deposition method

Abstract

The unique structural properties of vertically aligned graphene sheets or Carbon Nanowalls (CNWs) have attracted great interests for their potential for various applications in microelectronic devices, energy storage, and catalyst support materials. During the handling or operation of the devices, tension and/or pressure are often needed. Under such conditions, CNWs must undergo compression and stress. Therefore, the deformation mechanism and evolution behavior of the CNW structures under load play a critical role in the performance and reliability of the devices. In this study, the mechanical properties of a typical maze-like CNW structure synthesized by a Radial Injection Plasma Enhanced Chemical Vapor Deposition (RI-PECVD) technique were analyzed by employing the nanoindentation method. The measured compressive strength of the CNW structure was 50 MPa with an average modulus E value of ∼28 GPa, which is significantly higher than that of pyrolytic graphite and other graphene-based materials such as 3D graphene-derived carbon, commercial graphene, and reduced graphene oxide films. An elastoplastic behavior of a soft material was observed in high-resolution microscopy and a mechanism of deformation for CNWs is elucidated.