Orientation in large-area semiconducting 2-amino-anthracene thin films fabricated by dynamic floating film transfer method

In organic electronics, fabrication of stable, soluble, and uniform thin films of large surface area is highly important for a wide range of organic device applications. However, these objectives are difficult to achieve when using organic liquid crystalline molecules. This work focuses on a molecular organic material synthesized in our lab which was used to fabricate large-area thin films by applying the recently developed ribbon-shaped floating film transfer method (FTM). After establishing the most optimal casting parameters, organic molecule thin films of large surface area (up to 15 cm in length and 2 cm in width) were obtained. Subsequent polarized optical microscopy and atomic force microscopy investigations confirmed that film morphology and texture was uniform. Further, UV spectroscopy measurements using a polarizer were performed to study the pi-pi conjugation, indicating that the films exhibited optical anisotropy, as a Dichroic Ratio (DR) of 3.8 was obtained, with a 10 nm redshift in parallel FTM relative to the spin-coating method.