Small molecules based on bithiazole for solution-processed organic solar cells
摘要:
A series of donor-acceptor-donor small molecules (1-3) with bithiazole as acceptor unit, triphenylamine as donor unit and thiophene with different number (0, 1, 2) as bridge were synthesized by palladium(0)-catalyzed Suzuki or Stille coupling reactions. The thermal, optical, electrochemical, charge transport, and photovoltaic properties of these small molecules were examined. All compounds exhibit excellent thermal stability with decomposition temperatures (5% weight loss) over 390 degrees C in nitrogen atmosphere. As increasing the number of thiophene and pi-conjugation length of molecule, the absorption maximum in film red shifts from 406 to 498 nm, the extinction coefficient increases from 1.35 x 10(4) to 7.66 x 10(4) M (1) cm (1), and the optical band gap decreases from 2.6 to 2.0 eV. The electron- donating thiophene and bithiophene in compounds 2 and 3 up-shift HOMO energy level from -5.42 (1) to -5.24 eV (2) or -5.22 eV (3), and down-shift LUMO energy level from -2.48 (1) to -2.84 eV (2) or -2.81 eV (3). The hole mobility of compound 3 is up to 3.6 x 10 (4) cm(2) V (1) s (1), which is one order of magnitude higher than that of compound 2, but compound 1 shows no field- effect transistor performance. Solution-processed bulk heterojunction organic solar cells based on 1-3:PC71BM (1:4, w/w) blend films exhibit increasing power conversion efficiency (up to 2.61%) as increasing thiophene unit number. (c) 2012 Elsevier B.V. All rights reserved.
alternative copolymers containing bithiazole acceptor unit and the donor unit of carbazole (P1), dithienopyrrole (P2), or dithienosilole (P3) were synthesized for the application as donor materials in polymer solar cells (PSCs). The copolymers were characterized by TGA, UV−vis absorption, electrochemical cyclic voltammetry and photovoltaic measurements. The results indicate that the donor units in the copolymers
合成了三种新的供体-受体(D-A)替代共聚物,它们包含噻唑受体单元和咔唑(P1),二噻吩并吡咯(P2)或二噻吩甲硅烷基(P3)的供体单元,用作聚合物太阳能电池(PSC)中的供体材料)。所述共聚物通过TGA,UV-可见吸收,电化学循环伏安法和光伏测量来表征。结果表明,共聚物中的供体单元显着影响共聚物的带隙,电子能级和光伏性质。在这三种共聚物中,P3具有二噻吩甲硅油的供体单元的吸收光谱与P3HT相似,在-5.18 eV处具有合适的HOMO能级,在3.07×10 -4 cm 2 / V s下具有更高的空穴迁移率,并且具有良好的光伏性能。基于P3:PC 70 BM = 1:1(w / w)的PSC的功率转换效率达到2.86%,短路电流为7.85 mA / cm 2,开路电压为0.68 V,填充系数为0.535,在AM1.5的照度下为100 mW / cm 2。
Tandem photovoltaic cells
申请人:Konarka Technologies, Inc.
公开号:EP2261980A2
公开(公告)日:2010-12-15
Tandem photovoltaic cells, as well as related components, systems, and methods, are disclosed.