Solution‐Processed Chemically Non‐Destructive Filter Transfer of Carbon‐Nanotube Thin Films onto Arbitrary Materials

Abstract Filter‐transfer methods of single‐walled carbon‐nanotube (SWNT) thin films have been widely employed to fabricate state‐of‐the‐art electronics and photonics devices with highly transparent and conductive electrodes; however, a challenge remains for all solution‐processable technologies to overcome substrates’ destruction due to their solvent incompatibility. Here, an advanced method of transferring SWNT thin films onto arbitrary material substrates by adopting chemically stable and flexible polytetrafluoroethylene (PTFE) membranes is reported. Filtrated SWNT thin films on PTFE membranes (PTFE@SWNTs) press‐freely adhere to not only flat but curved substrates by their solvent‐wettability and flexibility natures, and are spontaneously transferred after low‐temperature evaporation of the wet solvents and peeling of the PTFE membrane. SWNT thin films transferred onto polyethylene terephthalate films show sheet resistance values of ≈400 Ω □ −1 at ≈90% transmittance, which are drastically decreased to ≈50 Ω □ −1 at ≈65% from ≈100 Ω □ −1 at ≈80%. The wet solvents are suitably displaced based on solvent‐compatibility experiments with the substrates. Topically, it is demonstrated that the solvent‐wetted PTFE@SWNT can be non‐destructively placed onto a perovskite (CH 3 NH 3 PbI 3 ) substrate via the as‐displaced various organic solvents. A pre‐doping process of PTFE@SWNTs is possible by using a HNO 3 aqueous solution. The HNO 3 ‐doped SWNT thin film is successfully transferred onto the perovskite substrate.