TY - JOUR AB - A new method to synthesize an electronrich building block cyclopentadithienothiophene (9Hthieno[3,2b]thieno[2″,3″:4′,5′]thieno[2′,3′:3,4]cyclopenta[1,2d]thiophene, CDTT) via a facile aromatic extension strategy is reported. By combining CDTT with 1,1dicyanomethylene3indanone endgroups, a promising nonfullerene small molecule acceptor (CDTTIC) is prepared. Ascast, singlejunction nonfullerene organic solar cells based on PFBDBT: CDTTIC blends exhibit very high shortcircuit currents up to 26.2 mA cm−2 in combination with power conversion efficiencies over 11% without any additional processing treatments. The high photocurrent results from the nearinfrared absorption of the CDTTIC acceptor and the wellintermixed blend morphology of polymer donor PFBDBT and CDTTIC. This work demonstrates a useful fused ring extension strategy and promising solar cell results, indicating the great potential of the CDTT derivatives as electronrich building blocks for constructing highperformance small molecule acceptors in organic solar cells. AU - He,Q AU - Shahid,M AU - Wu,J AU - Jiao,X AU - Eisner,FD AU - Hodsden,T AU - Fei,Z AU - Anthopoulos,TD AU - McNeill,CR AU - Durrant,JR AU - Heeney,M DO - 10.1002/adfm.201904956 EP - 7 PY - 2019/// SN - 1616-301X SP - 1 TI - Fused Cyclopentadithienothiophene acceptor enables ultrahigh shortcircuit current and high efficiency >11% in ascast organic solar cells T2 - Advanced Functional Materials UR - http://dx.doi.org/10.1002/adfm.201904956 UR - https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.201904956 UR - http://hdl.handle.net/10044/1/73100 VL - 29 ER -