The liquid crystal Click procedure for oligothiophene-tethered phthalocyanines – self-assembly, alignment and photocurrent

Abstract

A series of star-shaped liquid crystals (LCs) with a phthalocyanine donor core, oligothiophene antennae and fullerene acceptors have been successfully prepared. This hierarchical self-assembly results in a nanosegregated helical donor–acceptor–antennae LC-system promoted by the recently discovered Click procedure. This model system reveals all photophysical prerequisites for energy conversion, charge generation and transport. Uniform amorphous thin films of 150 nm could be produced by bar-coating. Annealing did not only induce the formation of columns via the Click procedure but also partially homeotropically aligned the non-clearing sample in a sandwich geometry (ITO and Ag/MoO₃). This has been confirmed by microscopic studies and the measurement of photocurrent, which increased by a factor of 300 after the annealing step.