Low band gap conjugated polymers consisting of alternating dodecyl thieno[3,4-b]thiophene-2-carboxylate and one or two thiophene rings: Synthesis and photovoltaic property

作者：Myung Jin Baek; Lee Soo Hyoung; Zong Kyukwan; Lee Youn Sik^*

来源：Synthetic Metals, 2010, 160(11-12): 1197-1203.

DOI：10.1016/j.synthmet.2010.03.008

• Conjugated polymer
• Thieno[3,4-b]thiophene
• Low band gap
• Photovoltaic device

In order to develop conjugated polymers with low band gaps and deep HOMO levels, copolymers consisting of alternating dodecyl thieno[3,4-b]thiophene-2-carboxylate and one (DTT-T(1)) or two thiophene rings (DTT-T(2)) were synthesized. The estimated optical band gap and HOMO level of DTT-T(1) and DTT-T(2) T(2) were similar to 1.58/1.61 and similar to-5.15/-5.20 eV, respectively, indicating that the polymers have relatively low band gaps and deep HOMO levels, as compared to many other reported polymers. Photovoltaic devices were fabricated using DTT-T2 and a fullerene derivative (PCBM), and whose power conversion efficiency was 0.21% under the illumination of AM 1.5 (100 mW/cm(2)). The low conversion efficiency of the devices was attributed to the inefficiency of exciton formation due to the low absorption coefficient and self-quenching of the polymer as well as the un-optimized device conditions.

• 出版日期2010-6