Dry-Transfer of Aligned Multiwalled Carbon Nanotubes for Flexible Transparent Thin Films

Figure 3

Patterned dry-transferred MWCNT thin films. (a) Patterning by Mo catalyst passivation. Al₂O_x/Fe bilayer catalyst patterned using laser-jet/paper transfer and Mo deposition. Patterned MWCNT films were transferred to the destination PC (as described in Figure 2). A self-assembled monolayer, APTES was employed for PET/ITO substrates prior to transfer. (b, e) An aligned MWCNT film patterned into 5 μm interdigitated electrodes by standard photolithography and O₂ RIE (0.2 mbar, 100 W, 120 s). Inset: optical micrograph of a Mo-passivated prepatterned CNT film shear transferred to a PET substrate and a second perpendicularly aligned prepatterned forest shear transferred. (c) AFM micrograph (900 nm × 900 nm) of a dry-transferred MWCNT film on a PC substrate. Inset: SEM micrograph of a transferred film showing the high level of macroscopic alignment. (d) Optical micrograph of poly(lysine)-treated (right) with a dry-transferred MWCNT film (left). Prior to treatment MWCNTs did not adhere. Inset: schematic of the substrate cross-section. (f) Transparency control by O₂ RIE with 5, 20, and 50 μm dots defined by conventional photolithography.