Characterization of a soluble anthradithiophene derivative

The structural and electrical properties of a solution processable material, 2,8-difluoro-5,11-tert-butyldimethylsilylethynyl anthradithiophene (TBDMS), were measured for single crystal transistors. TBDMS is observed to readily form single crystals from physical vapor zone sublimation. A columnar packing crystal structure, with an approximate π/4 radian rotational offset between neighboring molecules, is observed. Single crystal TBDMS transistors display a maximum observed saturation mobility μS of 0.07 cm2/V s, current on-off ratio >107, and subthreshold swing S≈1 dec/V. The spectral current noises of single crystal devices display a 1/f flicker noise, while the metal-semiconductor charge injection barrier is estimated by ultraviolet photoemission spectroscopy.