Remarkable Enhancement of Hole Mobility of Novel DA‐D’‐AD Small Molecules by Thermal Annealing: Effect of the D’‐Bridge Block

Conjugated small molecules are advanced semiconductor materials with attractive physicochemical and optoelectronic properties enabling the development of next‐generation electronic devices. The charge carrier mobility of small molecules strongly influences the efficiency of organic and hybrid electronics based on them. Herein, we report the synthesis of four novel small molecules and their investigation with regard to the impact of molecular structure and thermal treatment of films on charge carriers’ mobility. The benzodithiophene‐containing compounds (BDT) were shown to be more promising in terms of tuning the morphology upon thermal treatment. Impressive enhancement of hole mobilities by more than 50 times was found for annealed films based on a compound M4 comprising triisopropylsilyl‐functionalized BDT core. The results provide a favorable experience and strategy for the rational design of state‐of‐the‐art organic semiconductor materials (OSMs) and for improving their charge‐transport characteristics. Four novel conjugated small molecules (SM) are designed as organic semiconductor materials. Thermal treatment is shown as a powerful approach to control the morphology of SM‐based thin films. Remarkable enhancement of hole mobilities of ca. 50 times is achieved for films based on compounds with triisiopropylsilyl‐functionalized benzodithiophene cores.