An air-stable DPP-thieno-TTF copolymer for single-material solar cell devices and field effect transistors

Following an approach developed in our group to incorporate tetrathiafulvalene (TTF) units into conjugated polymeric systems, we have studied a low band gap polymer incorporating TTF as a donor component. This polymer is based on a fused thieno-TTF unit that enables the direct incorporation of the TTF unit into the polymer, and a second comonomer based on the diketopyrrolopyrrole (DPP) molecule. These units represent a donor–acceptor copolymer system, p(DPP-TTF), showing strong absorption in the UV–visible region of the spectrum. An optimized p(DPP-TTF) polymer organic field effect transistor and a single material organic solar cell device showed excellent performance with a hole mobility of up to 5.3 × 10–2 cm2/(V s) and a power conversion efficiency (PCE) of 0.3%, respectively. Bulk heterojunction organic photovoltaic devices of p(DPP-TTF) blended with phenyl-C71-butyric acid methyl ester (PC71BM) exhibited a PCE of 1.8%

Sulfur Containing Conjugated Polymers with Interesting Electronic Properties.

ABSTRACTThe electronic properties of the isomerie (C2S2)n conjugated sulfur containing polymers 1, 2, and 3 were characterized using ab initio and PRDDO Molecular orbital calculations, as well as EH band structure calculations. It is anticipated that such structures might exhibit enhanced electrical conductivities when doped owing to the possibility of the peripheral sulfur atoms extending orbital interactions transverse to the chain axis direction. Such increased dimensionality is demonstrated for the structurally similar superconductive Molecular TTF and ET charge-transfer salts. Of the three polymeric structures, indications are that polymer 2 is highest in energy. Polymer 3 can exist in both “chair” and “boat” conformations, with the chair form slightly more stable. Both the chair and boat forms of 3 were found to be of lower energy than 1. Calculated band gaps and band widths are reported along with preliminary synthetic attempts to prepare these polymers and observed properties.</jats:p