Department of Materials Science and Engineering, College of Engineering, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing, 100871, China.
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China.
Adv Mater. 2018 Mar;30(10). doi: 10.1002/adma.201705969. Epub 2018 Jan 15.
A fused tris(thienothiophene) (3TT) building block is designed and synthesized with strong electron-donating and molecular packing properties, where three thienothiophene units are condensed with two cyclopentadienyl rings. Based on 3TT, a fused octacylic electron acceptor (FOIC) is designed and synthesized, using strong electron-withdrawing 2-(5/6-fluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)-malononitrile as end groups. FOIC exhibits absorption in 600-950 nm region peaked at 836 nm with extinction coefficient of up to 2 × 10 m cm , low bandgap of 1.32 eV, and high electron mobility of 1.2 × 10 cm V s . Compared with its counterpart ITIC3 based on indacenothienothiophene core, FOIC exhibits significantly upshifted highest occupied molecular orbital level, slightly downshifted lowest unoccupied molecular orbital level, significantly redshifted absorption, and higher mobility. The as-cast organic solar cells (OSCs) based on blends of PTB7-Th donor and FOIC acceptor without additional treatments exhibit power conversion efficiencies (PCEs) as high as 12.0%, which is much higher than that of PTB7-Th: ITIC3 (8.09%). The as-cast semitransparent OSCs based on the same blends show PCEs of up to 10.3% with an average visible transmittance of 37.4%.
一种融合的三噻吩（3TT）砌块被设计并合成，具有强供电子和分子堆积性质，其中三个噻吩单元与两个环戊二烯基环缩合。基于 3TT，设计并合成了一种融合的八元环电子受体（FOIC），使用强吸电子的 2-(5/6-氟-3-氧代-2,3-二氢-1H-茚-1-亚基）丙二腈作为端基。FOIC 在 600-950nm 区域有吸收，在 836nm 处有峰值，消光系数高达 2×10 m cm ，低带隙为 1.32eV，电子迁移率高达 1.2×10 cm V s 。与基于茚并噻吩噻吩核心的 ITIC3 相比，FOIC 表现出明显的最高占据分子轨道能级上移，最低未占据分子轨道能级略微下移，明显的吸收红移，以及更高的迁移率。基于 PTB7-Th 给体和 FOIC 受体的无额外处理的共混物的铸造有机太阳能电池（OSC）表现出高达 12.0%的功率转换效率（PCE），远高于 PTB7-Th：ITIC3（8.09%）。基于相同共混物的铸造半透明 OSC 表现出高达 10.3%的 PCE，平均可见光透过率为 37.4%。
