Synthesis and Electronic Properties of Semiconducting Polymers Containing Benzodithiophene with Alkyl Phenylethynyl Substituents

Abstract

Semiconducting polymers containing benzodithiophene with decyl phenylethynyl and hexadecyl phenylethynyl substituents have been synthesized by Stille coupling polymerization. The optoelectronic properties of the synthesized polymers have been investigated. The synthesized polymers were tested in bulk heterojunction solar cells.

Benzo[1,2‐b:4,5‐b′]dithiophene Building Block for the Synthesis of Semiconducting Polymers

“…[ 18 ] Hu and co-workers [ 19 ] reported the syn-synthesized (Scheme 10 ). [23][24][25][26] The BDT monomer with pentyl phenylethynyl substituents was synthesized from the commercially available 4-pentylphenyl acetylene and 4,…”

“…By contrast, the homopolymers with decyl and hexadecyl substituents were found to be soluble in chloroform. [ 24 ] The homopolymers 17b and 17c were tested as donors in bulk heterojunction solar cells with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) acceptor. Power conversion effi ciency (PCE) of 1.1% was measured for the homopolymer 15b .…”

“…Power conversion effi ciency (PCE) of 1.1% was measured for the homopolymer 15b . [ 24 ] Homopolymer 17b was also tested in OFET and a fi eld-effect mobility of 1.10 × 10 − 3 cm 2 (V · s) − 1 was measured on a fl uorosilane-treated OFET device. [ 27 ] Ferraris and co-workers [ 28 ] reported the synthesis of a BDT homopolymer containing dialkylthio substituents (Scheme 12 ).…”

Donor–acceptor semiconducting polymers for organic solar cells

“…However, the HOMO of the DTP 0 ]dithiophene (BDT) is the most used donor building block for the synthesis of semiconducting polymers used in OFETs and BHJ solar cells. 45,[114][115][116] The BDT building block offers two advantages: the fused BDT allows the incorporation of substituents on the central benzene core while maintaining the planarity of the two thiophene units, and the symmetric nature of the BDT monomer eliminates the need of controlling regioregularity during the polymerization. 114 Moreover, due to the large planar conjugated structure of the BDT unit, the polymer can easily forms pÀp stacks, which renders high charge carrier mobility.…”

“…45,[114][115][116] The BDT building block offers two advantages: the fused BDT allows the incorporation of substituents on the central benzene core while maintaining the planarity of the two thiophene units, and the symmetric nature of the BDT monomer eliminates the need of controlling regioregularity during the polymerization. 114 Moreover, due to the large planar conjugated structure of the BDT unit, the polymer can easily forms pÀp stacks, which renders high charge carrier mobility. 78 Taking these advantages into account, many groups have synthesized a variety of BDT D-A copolymers with tunable bandgaps and HOMO/LUMO energy levels.…”