Thiol-ene cross-linking of poly(fluorene) films with enhanced color stability

摘要

Poly(dialkyl fluorene)s are solution processable conjugated polymers with characteristic blue emission, chemical and thermal stability and high photoluminescent yields. However, a consistent problem has been an additional broad green emission in the 500-550 nm region associated with low energy aggregates or ketone defects. One way of removing this unwanted emission is by crosslinking: crosslinked conjugated polymers have better colour stability and also allow multilayer solution-processed devices to be formed. There are a number of reports of methods of crosslinking conjugated polymers including thermally initiated free radical autopolymerisation of styrene groups (which requires temperatures above 150°C) and various UV-initiated crosslinking processes (which require a photoinitiator that may have a deleterious effect on the film).