Germaindacenodithiophene based low band gap polymers for organic solar cells

Abstract

We report the first synthesis of a fused germaindacenodithiophene monomer and its polymerisation with 2,1,3-benzothiadiazole by Suzuki polycondensation. The resulting polymer, PGeTPTBT, is semicrystalline, despite the presence of four bulky 2-ethylhexyl groups. Blends with P(70)CBM afford solar cells with efficiencies of 5.02%.

Improved Charge Transport and Absorption Coefficient in Indacenodithieno[3,2‐b]thiophene‐based Ladder‐Type Polymer Leading to Highly Efficient Polymer Solar Cells

“…In particular, power conversion efficiency (PCE) of 8–9% in a single junction device has been demonstrated 1–5. Among various materials developed for BHJ devices, the multifused‐ring conjugated polymers are particularly interesting due to their superior optical and electrical properties 6–20. The highly fused aromatic/heteroaromatic units enhance effective conjugation of the polymer backbone to facilitate electron delocalization.…”

Marriage of heavy main group elements with π-conjugated materials for optoelectronic applications

“…4; 21-41). [57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72] The dithienogermole containing polymers are generally obtained by metal-catalyzed cross-coupling methodologies such as the Stille, Suzuki-Miyaura and Sonogashira reactions, and very high number average molecular weights (M n ) of up to 133000 g mol -1 have been occasionally reported. Due to d-block contraction, 73,74 the electronegativity of germanium is slightly closer to carbon than the related silicon species, 75 therefore reducing the polarization of the Ge-C bond and rendering aryl germanes more tolerable towards bases and nucleophiles than the related aryl silanes.…”

“…63,69,[85][86][87][88][89][90] The previously mentioned polymer 21 originally synthesized by Heeney and coworkers was also examined as a component of TFTs with a promising mobility of 0.11 cm 2 V -1 s -1 noted. 87 Similarly, the previously described dithienogermole and germafluorene copolymers 54-60 ( Fig.…”

A Novel Alkylated Indacenodithieno[3,2‐b]thiophene‐Based Polymer for High‐Performance Field‐Effect Transistors

“…For example, changing the alkyl side‐chains on the IDT to phenyl alkyl groups reduced the reported charge carrier mobility, whilst retaining the linear alkyl side‐chains and varying the comonomer has also reduced charge carrier mobility in all reported examples . Changing the bridging atoms on the IDT unit from carbon to silicon or germanium also resulted in a reduction of the reported charge carrier mobility …”