A diketopyrrolopyrrole molecule end-capped with furan-2-carboxylate moiety: planarity of molecular g

• 作 者: FeiZhang[1]WeifeiFu[1]PeiCheng[2]ZhixinXie[1]CongChengFan[1]MinminShi[1]LeiFu[1]JianhuiHou[2]XiaoweiZhan[3]HongzhengChen[1]
• 机 构: MOE Key Laboratory of Macromolecular Synthesis and Functionalization,State Key Lab of Silicon Materi
• 出 处: 中国化学会第29届学术年会
• 发表日期: 2014年期

　　Adiketopyrrolopyrrole(DPP)molecule with fully-planar molecular geometry,3,6-bis{5-[(ethylfuran-2-carboxylate)-2-yl]thiophene-2-yl}-2,5-bis(2-ethylhexyl)pyrrolo[3,4-c]pyrrole-1,4-dione(DPP(CF)2)was designed and synthesized,for solution-processable organic solar cells(OSCs).It is theoretically calculated that the dihedral angels between the two furan-2-carboxylate end-groups and DPP core are both only 0.56°.Due to this negligible steric distortion,the molecular conformation of DPP(CF)2 can be considered fully coplanar,leading to a higher crystallinity for DPP(CF)2 film.As a result,the hole mobility of DPP(CF)2 is one order of magnitude higher than that of the DPP derivative with thiophene-2-carboxylate as the end-group(DPP(CT)2)[1].OSCs based on the blends of DPP(CF)2 or DPP(CT)2 and PC 71 BM were fabricated.It is found that the DPP(CF)2-based devices exhibit much better photovoltaic performance than the DPP(CT)2-based devices,with the highest power conversion efficiency of 5.37%and a short-circuit current density of 11.4 mA cm-2.This phenomenon can be ascribed to the superior charge-transporting ability of DPP(CF)2 caused by its fully-planar molecular geometry [2].