Impact of static and dynamic disorder effects on the charge transport properties of merocyanine single crystals†

Merocyanines are polar organic π-conjugated molecules consisting of electronic donor (D) and acceptor (A) subunits connected via a conjugated bridge. They have been investigated because of their unique self-assembly and optoelectronic properties, making them ideal active materials for organic electronic applications. The understanding of their charge transport properties at the nanoscale is very challenging and mostly an unexplored field. We report a theoretical study on modelling the hole transport parameters and mobility, together with the investigation of the structure–property relationships of seven merocyanine single crystals, consisting of different combinations of D–A units. We critically discuss the impact of both static (energetic) and dynamic (thermal) disorder effects on charge mobility and transport networks, by emphasizing the importance of including such contributions for an in-depth understanding of the charge transport properties of polar organic semiconductors.