Porphyrin−Dithienothiophene π-Conjugated Copolymers: Synthesis and Their Applications in Field-Effect Transistors and Solar Cells

Abstract

Soluble conjugated alternating porphyrin-dithienothiophene copolymersssingle-bond linked (I) and triple-bond linked (IIa and IIb)swere synthesized by palladium(0)-catalyzed Stille and Sonagashira coupling reactions, respectively. The thermal, electrochemical, optical, charge transport, and photovoltaic properties of these copolymers were examined; the effect of the triple bond was studied. I exhibits onset decomposition temperature (T d ) of 410°C and glass-transition temperature (T g ) of 180°C, higher than those of IIb (T d , 330°C; T g , 130°C). The absorption spectrum of I in thin film exhibits a sharp Soret band at 450 nm and two weak Q-bands at 563-619 nm, while IIb exhibits a sharp Soret band at 491 nm and a strong Q-band at 760 nm. The emission maxima of I and IIb in solution are located at 642 and 722 nm respectively. IIb is electrochemically active in both the oxidation and reduction regions, while I shows only oxidation peak. The field-effect hole mobilities as high as 2.1 × 10 -4 cm 2 V -1 s -1 were obtained for these copolymers. Polymer solar cells (PSCs) were fabricated based on the blend of the polymers and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM). The power conversion efficiency (PCE) of 0.3% was achieved under AM 1.5, 100 mW/cm 2 for the PSC using IIb:PCBM (1:3, w/w) as active layer. The PCE of the PSC based on IIb:PCBM (1:3, w/w) is double that based on I:PCBM (1:2, w/w), consistent with that IIb exhibits stronger Q-band absorption and higher mobility at room temperature.

Porphyrin polymers and organic frameworks

“…109 Two systems were analyzed which contained porphyrin-conjugated ethynyl groups to increase conjugation along the porphyrin polymer backbone and improve photoconversion efficiency (Figs 39(f ) and (g)). Interestingly, a similar porphyrin monomer synthesized and tested in a porphyrin:PCBM solar cell has achieved a solar conversion efficiency of 7% by using a trans porphyrin configuration with ethynyl substituents, allowing for greater -conjugation between porphyrin and side pyrrole-pyrrole acceptor substituents.…”

Organometallic Approaches to Conjugated Polymers for Plastic Solar Cells: From Laboratory Synthesis to Industrial Production

“…In previous works we have widely exploited this reaction in the synthesis both of polymers and of molecules with PAE structure. [47] A recent report by Bo and co-workers [48] pointed out the possible impact of introduction of acetylenic bridges between the D and A units in D-A copolymers. Ethynylene-bridged porphyrin- [49] prepared a series of PAEs bearing triphenylamine (TPA) units; these show excellent hole-transporting properties (Scheme 17).…”

Synthesis and photocatalytic activity of V-doped mesoporous TiO2 photosensitized with porphyrin supported by SBA-15

“…On the other hand, the aggregation of dye molecules is a main factor affecting the performance of dye-sensitized systems [43]. In dye-sensitized solar cells, Fig.…”