A Planar Copolymer for High Efficiency Polymer Solar Cells

Abstract

An alternating copolymer, poly(2-(5-(5,6-bis(octyloxy)-4-(thiophen-2-yl)benzo[c][1,2,5]thiadiazol-7-yl)thiophen-2-yl)-9-octyl-9H-carbazole) (HXS-1), was designed, synthesized, and used as the donor material for high efficiency polymer solar cells. The close packing of the polymer chains in the solid state was confirmed by XRD. A J(sc) of 9.6 mA/cm(2), a V(oc) of 0.81 V, an FF of 0.69, and a PCE of 5.4% were achieved with HXS-1 and [6,6]-phenyl C(71)-butyric acid methyl ester (PC(71)BM) as a bulk heterojunction active layer spin-coated from a solvent mixture of 1,2-dichlorobenzene and 1,8-diodooctane (97.5:2.5) under air mass 1.5 global (AM 1.5 G) irradiation of 100 mW/cm(2).

Design and synthesis of soluble dibenzosuberane-substituted fullerene derivatives for bulk-heterojunction polymer solar cells

“…To further improve device performance, the effect of solvent additive was investigated. Recently, solvent additives have been reported to enhance the device performance by improving the inter-penetrating D/A network structure [37,38,41]. Herein, we introduced a widely used additive 1,8-diiodooctane (DIO) and improved device performance was observed, as seen in Fig.…”

Donor–acceptor semiconducting polymers for organic solar cells

“…69 The reported high FF indicated that a balanced charge transport could be achieved by improving the morphology of the active layer blend upon the addition of DIO additive. 72 After changing the solvent from chloroform to dichlorobenzene and addition of 3.0% DIO, the PCE of the polymer 12a increased to 3.41% (J SC ¼ 7.29 mA cm…”

“…68 Zhang et al synthesized D-A polymer 10f with an electron donating alkoxy group attached to the acceptor moiety which increased the HOMO by 0.2 eV when compared with the polymer 10a. 69 Polymer 10f exhibited an initial PCE of 2.75% (…”

Incremental optimization in donor polymers for bulk heterojunction organic solar cells exhibiting high performance

“…17 Similar enhancement of the PCE has been observed for devices based on HSX-1/PC 71 BM devices. 23 The extent of improvement of morphology of the active layer depends on the choice of additive and it's compatibility with the polymer fullerene system. For example, Li et al reported a significant improvement in PCE (4.86 !…”