UV-Sensitive Self-Assembled Monolayer Photoresist for the Selective Deposition of Carbon Nanotubes

The use of a UV-sensitive self-assembled monolayer photoresist to selectively deposit single-walled carbon nanotubes from solution using heterogeneous surface wettability is reported. This process combines ubiquitous photopatterning techniques with simple solution processing to yield highly selective and densely packed carbon nanotube patterns. The key mechanism is the change in surface chemistry caused by the UV-induced monolayer reaction. Selective deposition of carbon nanotubes was achieved by drop-casting the CNT solution onto the photopatterned substrates where the CNT solution only wets the exposed areas. Several compounds were employed, each with unique end groups that yield a range of surface energies. The selectivity is dependent on the contrast in the surface wettability. Increased selectivity was achieved by tuning the surface energy with addition of alcohol or a nonionic surfactant.