Heteroalkyl‐Substitution in Molecular Organic Semiconductors: Chalcogen Effect on Crystallography, Conformational Lock, and Charge Transport. (31st March 2022)

• Record Type: Journal Article
• Authors: Afraj, Shakil N.; Lin, Chia‐Chi; Velusamy, Arulmozhi; Cho, Chang‐Hui; Liu, Hsin‐Yi; Chen, Jianhua; Lee, Gene‐Hsiang; Fu, Jui‐Chen; Ni, Jen‐Shyang; Tung, Shih‐Huang; Yau, Shuehlin; Liu, Cheng‐Liang; Chen, Ming‐Chou; Facchetti, Antonio
• Is Part Of: Advanced functional materials. Volume 32:Number 27(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-31
• Subjects: chalcogen -- dithienothiophene -- high‐performance -- organic field effect transistors -- selenoalkylated bithiophene -- solution processable; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202200880
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The effect of heteroalkyl (‐XR, X = Se, S, O) substitution on a series of molecular semiconductors having a 3, 3′‐diheteroalkyl‐2, 2′‐bithiophene (XBT) central core is studied. Thus, the selenotetradecyl (‐SeC14 H29 ) SeBT core is investigated by end‐functionalization with two dithienothiophene (DTT), thienothiophene (TT), and thiophene (T) units to give SeBTs 1 –3, respectively, for molecular π‐conjugation effect examination. Furthermore, the selenodecyl (‐SeC10 H21 ) and selenohexyl (‐SeC6 H13 ) SeBT cores end‐capped with DTTs to give SeBTs 1B and 1C, respectively, are synthesized for understanding ‐SeR length effects. To address systematically the impact of the chalcogen heteroatom, the newly developed selenoalkyl SeBTs are compared with the previously reported thiotetradecyl (‐SC14 H29 ) DDTT‐SBT (4 ) and the new tetradecyloxy (‐OC14 H29 ) DDTT‐OBT (5 ). When fabricating organic field effect transistors by the solution‐shearing method, the devices based on the tetradecylated DDTT‐SeBT (1 ) exhibit the highest mobility up to 4.01 cm 2 V −1 s −1, which is larger than those of the other SeBT compounds and both DDTT‐SBT (4 ) (1.70 cm 2 V −1 s −1 ) and DDTT‐OBT (5 ) (9.32 × 10 −4 cm 2 V −1 s −1 ). These results are rationalized by a combination of crystallographic, morphological, and microstructural analysis. Abstract : The effect of heteroalkyl (‐XR, X = O, S, Se) substitution on a series of small molecule semiconductors having a 3, 3′‐diheteroalkyl‐2, 2′‐bithiophene central cores are studied. Solution‐processed DDTT‐SeBT (1 ) organic field effect transistors exhibit high hole mobility of 4.01 cm 2 V −1 s −1, far surpassing those of the corresponding SBT and OBT compounds.