Presentation Information
[8a-S202-5]Development of novel semiconducting polymers with thiazole-fused ring structures for organic photovoltaics
〇(M2)Mayu Tomita1, Yamanaka Kodai1, Mikie Tubasa1, Osaka Itaru1 (1.Hiroshima Univ.)
Keywords:
Organic photovoltaics,pi-Conjugated polymers,non fullerene acceptor (NFA)
The development of high-performance donor polymers is essential for enhancing the power conversion efficiency (PCE) of organic photovoltaics (OPVs). Our group has focused on thiazole-based building blocks, which offer both deep highest occupied molecular orbital (HOMO) energy levels—attributed to their strong electron-deficient nature—and rigid polymer backbones, enforced by intramolecular noncovalent interactions between the nitrogen atom in thiazole and the sulfur atom in an adjacent thiophene ring.
Among these, thienobenzobisthiazole (TBTz) has demonstrated particular promise, providing not only a deep HOMO level and a rigid backbone, but also good solubility in organic solvents. A polymer incorporating TBTz achieved a PCE exceeding 17%. To further enhance molecular packing, we previously developed π-extended thiazole-based units (i-TNTz and TTBTz), which feature bent molecular geometries. However, the resulting polymers (Pi-TNTzE and PTTBTzE) exhibited limited efficiencies, with PCEs of up to 13%. We attributed this suboptimal performance to backbone distortion caused by steric repulsion between intramolecular alkyl side chains, induced by the bent geometry.
To overcome this limitation, we designed a new π-extended, yet planar, thiazole-based core named TNTz. In this work, we report the synthesis of a donor polymer (PTNTzE) incorporating TNTz and investigate its optoelectronic properties and device performance. Notably, an OPV device based on PTNTzE, when combined with the non-fullerene acceptor L8-BO, delivered a high PCE of 17.8%.
Among these, thienobenzobisthiazole (TBTz) has demonstrated particular promise, providing not only a deep HOMO level and a rigid backbone, but also good solubility in organic solvents. A polymer incorporating TBTz achieved a PCE exceeding 17%. To further enhance molecular packing, we previously developed π-extended thiazole-based units (i-TNTz and TTBTz), which feature bent molecular geometries. However, the resulting polymers (Pi-TNTzE and PTTBTzE) exhibited limited efficiencies, with PCEs of up to 13%. We attributed this suboptimal performance to backbone distortion caused by steric repulsion between intramolecular alkyl side chains, induced by the bent geometry.
To overcome this limitation, we designed a new π-extended, yet planar, thiazole-based core named TNTz. In this work, we report the synthesis of a donor polymer (PTNTzE) incorporating TNTz and investigate its optoelectronic properties and device performance. Notably, an OPV device based on PTNTzE, when combined with the non-fullerene acceptor L8-BO, delivered a high PCE of 17.8%.