Growing micropatterned CNT arrays on aluminum substrates using hot-filament CVD process

Abstract

Attempts to grow carbon nanotubes directly on to aluminum (Al) substrates have had limited success, primarily due to its relatively low melting point of 660°C. In this work, we have successfully synthesized vertically aligned CNTs (VACNTs) in a planar configuration (48µm tall) as well as, for the first time, a micropatterned array with 36µm tall CNTs on Al substrates. This was achieved by combining conventional microfabrication steps for patterning an array and a catalyst-assisted hot-filament CVD process with methane as carbon source gas for CNT synthesis. Such substrates can provide highly conductive and high specific surface area host materials for cathodes in lithium ion batteries and supercapacitors. We have demonstrated a >10× increase in surface area available for coating cathode nanoparticles in the 3D micropatterned CNT array, as compared to the planar configuration.