Effects of π-Conjugated Bridges on Photovoltaic Properties of Donor-π-Acceptor Conjugated Copolymers
作者:Xiaochen Wang、Yeping Sun、Song Chen、Xia Guo、Maojie Zhang、Xiaoyu Li、Yongfang Li、Haiqiao Wang
DOI:10.1021/ma202656b
日期:2012.2.14
to 3.72% for P(BDT-T-BT) and to 4.93% for P(BDT-TT-BT). Compared to furan and thiophene, thieno[3,2-b]thiophene π-bridge in the copolymers shows superior photovoltaic performance. The results indicate that the photovoltaic performance of some high efficiency D–A copolymers reported in literatures could be improved further by inserting suitable π-bridges.
基于苯并二噻吩(BDT )的一系列共轭施主(D)-π-受体(A)共聚物P(BDT-F-BT),P(BDT-T-BT)和P(BDT-TT-BT)通过钯催化的斯蒂勒偶联法设计合成了供体单元和具有不同π桥的苯并噻二唑(BT)受体单元。所述BDT供体单元和受体BT单元之间的π-桥是呋喃(˚F)在P(BDT-F-BT),噻吩(Ť中)P(BDT-T-BT)和噻吩并[3,2- b ]噻吩(TT)在P(BDT-TT-BT)。已经发现,π-桥显着影响共聚物的分子结构和光电性能。随着呋喃到噻吩,然后到噻吩并[3,2- b ]噻吩的π桥变化,分子链的形状逐渐从z形变为几乎直线。的带隙P(BDT-F-BT),P(BDT-T-BT)和P(BDT-TT-BT),从1.96至1.82调谐到1.78电子伏特与HOMO能级向上移从-5.44到-5.35至-5.21 eV。以聚合物为施主和PC 71 BM为受体的块状异质结太
Correlation of intermolecular packing distance and crystallinity of D-A polymers according to π-spacer for polymer solar cells
作者:Tae Ho Lee、Min Hee Choi、Sung Jae Jeon、Doo Kyung Moon
DOI:10.1016/j.polymer.2016.07.082
日期:2016.9
Donor-acceptor-type polymers, PBDPBT-T, PBDPBT-TT, and PBDPBT-biT, were polymerized via Stille coupling reactions. In the unfavorable mode of DFT calculations, the distance between BDP in the two different polymer main chains showed different distance of repeating unit (Dn) according to the pi-spacers type. Especially, PBDPBT-TT caused larger D2 than PBDPBT-T and PBDPBT-biT. The UV-vis absorption spectra of PBDPBT-T and PBDPBT-biT films were red-shifted compared with the solution absorption, whereas that of a PBDPBT-TT film was blue-shifted. PBDPBT-T and PBDPBT-biT had high crystallinity and a tendency of face-on orientation. In contrast, PBDPBT-TT had low crystallinity. Owing to differences in packing formation, the polymers had different J(SC) values. When a polymer solar cell device was fabricated through a solution process, PBDPBT-biT (in a 1:1.5 ratio with PC70BM) exhibited a PCE of 4.50%, with a J(SC) value of 8.6 mA/cm(2), a V-OC value of 0.88 V, and an FF value of 59.4%. (C) 2016 Elsevier Ltd. All rights reserved.
How do we get across? Impact of bridging aromatic units on the optical, electronic, and photovoltaic properties of donor-acceptor polymers
A series of donor - π - acceptor (D- π -A) typepolymers (P1, P2, and P3) containing benzodithiophene (BDT) as donorunit and benzothiadiazole (BT) as acceptorunit were designed and synthesized by incorporating diverse electron-rich π bridges as thiophene (T), selenophene (Se) and thieno[3,2-b] thiophene (TT) via Pd-catalyzed Stille cross-coupling reaction. The effect of the various π-bridges on the