Solution Processable Pseudo <i>n</i>-Thienoacenes via Intramolecular S···S Lock for High Performance Organic Field Effect Transistors
Sureshraju Vegiraju, Xian-Lun Luo, Long-Huan Li, Shakil N. Afraj, Chi Lee, Ding Zheng, Hsin-Chun Hsieh, Chia‐Chi Lin, Shao‐Huan Hong, Hsin-Chia Tsai, Gene‐Hsiang Lee, Shih‐Huang Tung, Cheng‐Liang Liu, Ming-Chou Chen, Antonio Facchetti
Abstract
New solution processable 3,5-dithioalkyl dithienothiophene (DSDTT) based small molecular semiconductors end functionalized with various (fused) thiophenes including dithienothiophene (DTT), thienothiophene (TT), and thiophene (T) are synthesized and characterized in organic field effect transistors (OFETs). The new DSDTT core was synthesized via a one-pot [1 + 1 + 1] methodology. For comparison, non-thiolated 3,5-dialkyl dithienothiophene (DRDTT) based molecules are also prepared and characterized. Optical, electrochemical, and computed electronic structures of these molecules are investigated and contrasted. Single crystal data support evidence of S(alkyl)···S(thiophene) intramolecular locks, with a very short intramolecular S–S distance of 3.17 Å, planarizing the structure as for the equivalent extended n-thienoacenes. Via a solution-shearing semiconductor film deposition method, these semiconductors exhibit a OFET hole mobility up to 2.6 cm2 V–1 s–1, the greatest reported to date for fused/all-thiophene based small molecular organic semiconductors.