Patterning Liquid Crystalline Organic Semiconductors via Inkjet Printing for High-Performance Transistor Arrays and Circuits

Liquid crystalline (LC) organic semiconductors having long-range-ordered LC phases hold great application potential in organic field-effect transistors (OFETs). However, to meet real device application requirements, it is a prerequisite to precisely pattern the LC film at desired positions. Here, a facile method that combines the technique of inkjet printing and melt processing to fabricate patterned LC film for achieving high-performance organic integrated circuits is demonstrated. Inkjet printing controls the deposition locations of the LC materials, while the melt processing implements phase transition of the LC materials to form high-quality LC films with large grain sizes. This approach enables to achieve patterned growth of high-quality 2,7-dioctyl[1]-benzothieno[3,2-b][1]benzothiophene (C-8-BTBT) LC films. The patterned C-8-BTBT LC film-based 7 x 7 OFET array has 100% die yield and shows high average mobility of 6.31 cm(2) V-1 s(-1), along with maximum mobility up to 9.33 cm(2) V-1 s(-1). As a result, the inverters based on the patterned LC films reach a high gain up to 23.75 as well as an ultrahigh noise margin over 81.3%. Given the good generality of the patterning process and the high quality of the resulting films, the proposed method paves the way for high-performance organic integrated devices.

Automated summary

The study demonstrates a facile method combining inkjet printing and melt processing to fabricate high-quality LC films for organic integrated circuits, enabling patterned growth of 2,7-dioctyl[1]-benzothieno[3,2-b][1]benzothiophene (C-8-BTBT) LC films with high performance in OFETs.