STED-inspired optical lithography beyond acrylates

STED-inspired sub-diffractional nanolithography was so far restricted to free radical polymerization, predominantly of (meth)acrylates. We now expand the STED-inspired toolkit to cationic and oxidative polymerization, comprising the technologically important classes of epoxides and π-conjugated polymers. In both cases, we achieved structure sizes below 100 nm using transient state absorption depletion (TAD) in systems comprising onium salts as initiators and photosensitizers that can be depleted by transient state absorption.