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The growing demand for waste heat energy recovery from electronic devices, solar energy, and industrial production has led to increased attention on thermoelectric materials. In the past decades, significant progress has been achieved in inorganic thermoelectric materials. Moreover, flexible, lightweight, and bio-friendly organic thermoelectric (OTE) materials have emerged as promising candidates for thermoelectric devices. In particular, quinoidal conjugated small molecules and polymers with high mobility are suitable for thermoelectric conversion. Such kind of materials have gained increasing research interest due to their unique structural features and characteristics of polarons’ delocalization. Concurrently, quinoidal materials with high mobility and conductivity have been developed, and their use for thermoelectric conversion has been increasingly reported. This perspective summarizes the recent advancements in the design and synthesis of quinoidal conjugated small molecules and polymers, their advantages for thermoelectric conversion, and the latest reports on their charge carrier transport mechanisms. Moreover, to further enhance the TE performances of quinoidal materials, the existing challenges are discussed and the future developments are also outlooked.
Zhang, Q.; Chere, E. K.; Sun, J. Y.; Cao, F.; Dahal, K.; Chen, S.; Chen, G.; Ren, Z. F. Studies on thermoelectric properties of n-type polycrystalline SnSe1− x S x by iodine doping. Adv. Energy. Mater. 2015, 5, 1500360.
Zhao, L. D.; Lo, S. H.; Zhang, Y. S.; Sun, H.; Tan, G. J.; Uher, C.; Wolverton, C.; Dravid, V. P.; Kanatzidis, M. G. Ultralow thermal conductivity and high thermoelectric figure of merit in SnSe crystals. Nature 2014, 508, 373–377.
Tan, Q.; Zhao, L. D.; Li, J. F.; Wu, C. F.; Wei, T. R.; Xing, Z. B.; Kanatzidis, M. G. Thermoelectrics with earth abundant elements: Low thermal conductivity and high thermopower in doped SnS. J. Mater. Chem. A 2014, 2, 17302–17306.
Han, Y. M.; Zhao, J.; Zhou, M.; Jiang, X. X.; Leng, H. Q.; Li, L. F. Thermoelectric performance of SnS and SnS-SnSe solid solution. J. Mater. Chem. A 2015, 3, 4555–4559.
Lee, J.; Kim, J.; Moon, W.; Berger, A.; Lee, J. Enhanced Seebeck coefficients of thermoelectric Bi2Te3 nanowires as a result of an optimized annealing process. J. Phys. Chem. C 2012, 116, 19512–19516.
Scheele, M.; Oeschler, N.; Meier, K.; Kornowski, A.; Klinke, C.; Weller, H. Synthesis and thermoelectric characterization of Bi2Te3 nanoparticles. Adv. Funct. Mater. 2009, 19, 3476–3483.
Zhang, J. B.; Cheng, P.; Zhang, C. C.; Ding, G. F.; Duan, L.; Shao, J.; Wang, Q. MEMS-based platinum–platinum rhodium film temperature sensor on alumina substrate. J. Eng. 2016, 2016, 315–317.
Nejad, G. R. G.; Rahmani, F.; Abaeiani, G. R. Design and optimization of beta-cell temperature sensor based on 63Ni-Si. Appl. Radiat. Isot. 2014, 86, 46–51.
Chiang, C. T.; Chang, F. W. Design of a calibrated temperature difference sensor transducer for monitoring environmental temperature difference applications. IEEE Sens. J. 2016, 16, 1038–1043.
Abdul-Wahab, S. A.; Elkamel, A.; Al-Damkhi, A. M.; Al-Habsi, I. A.; Al-Rubai’ey’, H. S.; Al-Battashi, A. K.; Al-Tamimi, A. R.; Al-Mamari, K. H.; Chutani, M. U. Design and experimental investigation of portable solar thermoelectric refrigerator. Renewable Energy 2009, 34, 30–34.
Chen, L. G.; Meng, F. K.; Sun, F. R. Effect of heat transfer on the performance of thermoelectric generator-driven thermoelectric refrigerator system. Cryogenics 2012, 52, 58–65.
Tang, H. R.; Liang, Y. Y.; Liu, C. C.; Hu, Z. C.; Deng, Y. F.; Guo, H.; Yu, Z. D.; Song, A.; Zhao, H. Y.; Zhao, D. K. et al. A solution-processed n-type conducting polymer with ultrahigh conductivity. Nature 2022, 611, 271–277.
Lu, Y.; Yu, Z. D.; Un, H. I.; Yao, Z. F.; You, H. Y.; Jin, W. L.; Li, L.; Wang, Z. Y.; Dong, B. W.; Barlow, S. et al. Persistent conjugated backbone and disordered lamellar packing impart polymers with efficient N-doping and high conductivities. Adv. Mater. 2021, 33, 2005946.
Fan, Z.; Du, D. H.; Guan, X.; Ouyang, J. Y. Polymer films with ultrahigh thermoelectric properties arising from significant Seebeck coefficient enhancement by ion accumulation on surface. Nano Energy 2018, 51, 481–488.
Yan, X. W.; Xiong, M.; Li, J. T.; Zhang, S.; Ahmad, Z.; Lu, Y.; Wang, Z. Y.; Yao, Z. F.; Wang, J. Y.; Gu, X. D. et al. Pyrazine-flanked diketopyrrolopyrrole (DPP): A new polymer building block for high-performance n-type organic thermoelectrics. J. Am. Chem. Soc. 2019, 141, 20215–20221.
Chi, C.; Liu, G. Z.; An, M.; Zhang, Y. F.; Song, D. X.; Qi, X.; Zhao, C. Y.; Wang, Z. Q.; Du, Y. Z.; Lin, Z. Z. et al. Reversible bipolar thermopower of ionic thermoelectric polymer composite for cyclic energy generation. Nat. Commun. 2023, 14, 306.
Malik, Y. T.; Akbar, Z. A.; Seo, J. Y.; Cho, S.; Jang, S. Y.; Jeon, J. W. Self-healable organic–inorganic hybrid thermoelectric materials with excellent ionic thermoelectric properties. Adv. Energy Mater. 2022, 12, 2103070.
Zhang, Y. C.; Ye, D. K.; Li, M. X.; Zhang, X.; Di, C. A.; Wang, C. Solid state ionics enabled ultra-sensitive detection of thermal trace with 0.001 K resolution in deep sea. Nat. Commun. 2023, 14, 170.
Shi, Y. Q.; Li, J. F.; Sun, H. D.; Li, Y. C.; Wang, Y. M.; Wu, Z. A.; Jeong, S. Y.; Woo, H. Y.; Fabiano, S.; Guo, X. G. Thiazole imide-based all-acceptor homopolymer with branched ethylene glycol side chains for organic thermoelectrics. Angew. Chem., Int. Ed. 2022, 61, e202214192.
Zhao, W. R.; Ding, J. M.; Zou, Y.; Di, C. A.; Zhu, D. B. Chemical doping of organic semiconductors for thermoelectric applications. Chem. Soc. Rev. 2020, 49, 7210–7228.
Scaccabarozzi, A. D.; Basu, A.; Aniés, F.; Liu, J.; Zapata-Arteaga, O.; Warren, R.; Firdaus, Y.; Nugraha, M. I.; Lin, Y. B.; Campoy-Quiles, M. et al. Doping approaches for organic semiconductors. Chem. Rev. 2022, 122, 4420–4492.
Yuan, D. F.; Liu, W. Y.; Zhu, X. Z. Efficient and air-stable n-type doping in organic semiconductors. Chem. Soc. Rev. 2023, 52, 3842–3872.
Kim, G. H.; Shao, L.; Zhang, K.; Pipe, K. P. Engineered doping of organic semiconductors for enhanced thermoelectric efficiency. Nat. Mater. 2013, 12, 719–723.
Park, T.; Park, C.; Kim, B.; Shin, H.; Kim, E. Flexible PEDOT electrodes with large thermoelectric power factors to generate electricity by the touch of fingertips. Energy Environ. Sci. 2013, 6, 788–792.
Bubnova, O.; Khan, Z. U.; Wang, H.; Braun, S.; Evans, D. R.; Fabretto, M.; Hojati-Talemi, P.; Dagnelund, D.; Arlin, J. B.; Geerts, Y. H. et al. Semi-metallic polymers. Nat. Mater. 2014, 13, 190–194.
Sun, Y. M.; Sheng, P.; Di, C.; Jiao, F.; Xu, W.; Qiu, D.; Zhu, D. B. Organic thermoelectric materials and devices based on p- and n-type poly(metal 1,1,2,2-ethenetetrathiolate)s. Adv. Mater. 2012, 24, 932–937.
Ding, J. M.; Liu, Z. T.; Zhao, W. R.; Jin, W. L.; Xiang, L. Y.; Wang, Z. J.; Zeng, Y.; Zou, Y.; Zhang, F. J.; Yi, Y. P. et al. Selenium-substituted diketopyrrolopyrrole polymer for high-performance p-type organic thermoelectric materials. Angew. Chem., Int. Ed. 2019, 58, 18994–18999.
Yi, C.; Wilhite, A.; Zhang, L.; Hu, R. D.; Chuang, S. S. C.; Zheng, J.; Gong, X. Enhanced thermoelectric properties of poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate) by binary secondary dopants. ACS Appl. Mater. Interfaces 2015, 7, 8984–8989.
Patel, S. N.; Glaudell, A. M.; Peterson, K. A.; Thomas, E. M.; O’Hara, K. A.; Lim, E.; Chabinyc, M. L. Morphology controls the thermoelectric power factor of a doped semiconducting polymer. Sci. Adv. 2017, 3, e1700434.
Zhang, Q.; Sun, Y. M.; Xu, W.; Zhu, D. B. Thermoelectric energy from flexible P3HT films doped with a ferric salt of triflimide anions. Energy Environ. Sci. 2012, 5, 9639–9644.
Bubnova, O.; Berggren, M.; Crispin, X. Tuning the thermoelectric properties of conducting polymers in an electrochemical transistor. J. Am. Chem. Soc. 2012, 134, 16456–16459.
Zhang, Q.; Sun, Y. M.; Xu, W.; Zhu, D. B. What to expect from conducting polymers on the playground of thermoelectricity: Lessons learned from four high-mobility polymeric semiconductors. Macromolecules 2014, 47, 609–615.
Chabinyc, M. L.; Toney, M. F.; Kline, R. J.; McCulloch, I.; Heeney, M. X-ray scattering study of thin films of poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-b]thiophene). J. Am. Chem. Soc. 2007, 129, 3226–3237.
He, H.; Ouyang, J. Y. Enhancements in the mechanical stretchability and thermoelectric properties of PEDOT:PSS for flexible electronics applications. Acc. Mater. Res. 2020, 1, 146–157.
Wang, D. Y.; Ding, J. M.; Dai, X. J.; Xiang, L. Y.; Ye, D. K.; He, Z. H.; Zhang, F. J.; Jung, S. H.; Lee, J. K.; Di, C. A. et al. Triggering ZT to 0.40 by engineering orientation in one polymeric semiconductor. Adv. Mater. 2023, 35, 2208215.
Han, J. F.; Tiernan, E.; Lee, T.; Chiu, A.; McGuiggan, P.; Adams, N.; Tomko, J. A.; Hopkins, P. E.; Thon, S. M.; Tovar, J. D. et al. A new polystyrene-poly(vinylpyridinium) ionic copolymer dopant for n-type all-polymer thermoelectrics with high and stable conductivity relative to the Seebeck coefficient giving high power factor. Adv. Mater. 2022, 34, 2201062.
Ma, W.; Shi, K.; Wu, Y.; Lu, Z. Y.; Liu, H. Y.; Wang, J. Y.; Pei, J. Enhanced molecular packing of a conjugated polymer with high organic thermoelectric power factor. ACS Appl. Mater. Interfaces 2016, 8, 24737–24743.
Lu, Y.; Yu, Z. D.; Zhang, R. Z.; Yao, Z. F.; You, H. Y.; Jiang, L.; Un, H. I.; Dong, B. W.; Xiong, M.; Wang, J. Y. et al. Rigid coplanar polymers for stable n-type polymer thermoelectrics. Angew. Chem., Int. Ed. 2019, 58, 11390–11394.
Lu, Y.; Yu, Z. D.; Liu, Y.; Ding, Y. F.; Yang, C. Y.; Yao, Z. F.; Wang, Z. Y.; You, H. Y.; Cheng, X. F.; Tang, B. et al. The critical role of dopant cations in electrical conductivity and thermoelectric performance of N-doped polymers. J. Am. Chem. Soc. 2020, 142, 15340–15348.
Shi, K.; Zhang, F. J.; Di, C. A.; Yan, T. W.; Zou, Y.; Zhou, X.; Zhu, D. B.; Wang, J. Y.; Pei, J. Toward high performance n-type thermoelectric materials by rational modification of BDPPV backbones. J. Am. Chem. Soc. 2015, 137, 6979–6982.
Lei, T.; Xia, X.; Wang, J. Y.; Liu, C. J.; Pei, J. “Conformation locked” strong electron-deficient poly(p-phenylene vinylene) derivatives for ambient-stable n-type field-effect transistors: Synthesis, properties, and effects of fluorine substitution position. J. Am. Chem. Soc. 2014, 136, 2135–2141.
Xiong, Y.; Tao, J. W.; Wang, R. H.; Qiao, X. L.; Yang, X. D.; Wang, D. L.; Wu, H. Z.; Li, H. X. A furan-thiophene-based quinoidal compound: A new class of solution-processable high-performance n-type organic semiconductor. Adv. Mater. 2016, 28, 5949–5953.
Anderson, C. L.; Dai, N.; Teat, S. J.; He, B.; Wang, S.; Liu, Y. Electronic tuning of mixed quinoidal-aromatic conjugated polyelectrolytes: Direct ionic substitution on polymer main-chains. Angew. Chem., Int. Ed. 2019, 58, 17978–17985.
Zhang, C.; Yuan, D. F.; Wu, H.; Gann, E.; Thomsen, L.; McNeill, C. R.; Di, C. A.; Zhu, X. Z.; Zhu, D. B. Insight into thin-film stacking modes of π-expanded quinoidal molecules on charge transport property via side-chain engineering. J. Mater. Chem. C 2017, 5, 1935–1943.
Liu, X. C.; He, B.; Anderson, C. L.; Kang, J.; Chen, T.; Chen, J. X.; Feng, S. Z.; Zhang, L. J.; Kolaczkowski, M. A.; Teat, S. J. et al. para-Azaquinodimethane: A compact quinodimethane variant as an ambient stable building block for high-performance low band gap polymers. J. Am. Chem. Soc. 2017, 139, 8355–8363.
Wen, J. J.; Qiu, F.; Liu, H.; Liu, X. Y.; Hu, H.; Duan, Y. X.; Wang, Z. H.; Zhang, L. syn/anti-Oligothienoacene diimides with up to 10 fused rings. Angew. Chem., Int. Ed. 2022, 61, e202112482.
Velusamy, A.; Yu, C. H.; Afraj, S. N.; Lin, C. C.; Lo, W. Y.; Yeh, C. J.; Wu, Y. W.; Hsieh, H. C.; Chen, J. H.; Lee, G. H. et al. Thienoisoindigo (TII)-based quinoidal small molecules for high-performance n-type organic field effect transistors. Adv. Sci. 2021, 8, 2002930.
Qin, L. Q.; Liu, X. Z.; Zhang, X.; Yu, J. W.; Yang, L.; Zhao, F. G.; Huang, M. F.; Wang, K. W.; Wu, X. X.; Li, Y. H. et al. Triplet acceptors with a D–A structure and twisted conformation for efficient organic solar cells. Angew. Chem., Int. Ed. 2020, 59, 15043–15049.
Liu, X. C.; He, B.; Garzón-Ruiz, A.; Navarro, A.; Chen, T. L.; Kolaczkowski, M. A.; Feng, S. Z.; Zhang, L. J.; Anderson, C. A.; Chen, J. W. et al. Unraveling the main chain and side chain effects on thin film morphology and charge transport in quinoidal conjugated polymers. Adv. Funct. Mater. 2018, 28, 1801874.
Huang, Y. M.; Egap, E. Open-shell organic semiconductors: An emerging class of materials with novel properties. Polym. J. 2018, 50, 603–614.
Das, S.; Wu, J. S. Polycyclic hydrocarbons with an open-shell ground state. Phys. Sci. Rev. 2017, 2, 20160109.
Ji, X. Z.; Fang, L. Quinoidal conjugated polymers with open-shell character. Polym. Chem. 2021, 12, 1347–1361.
Zeidell, A. M.; Jennings, L.; Frederickson, C. K.; Ai, Q. X.; Dressler, J. J.; Zakharov, L. N.; Risko, C.; Haley, M. M.; Jurchescu, O. D. Organic semiconductors derived from dinaphtho-fused S-indacenes: How molecular structure and film morphology influence thin-film transistor performance. Chem. Mater. 2019, 31, 6962–6970.
Shi, X. L.; Burrezo, P. M.; Lee, S.; Zhang, W. H.; Zheng, B.; Dai, G. L.; Chang, J. J.; Navarrete, J. T. L.; Huang, K. W.; Kim, D. et al. Antiaromatic bisindeno-[ n]thienoacenes with small singlet biradical characters: Syntheses, structures and chain length dependent physical properties. Chem. Sci. 2014, 5, 4490–4503.
Shi, X. L.; Lee, S.; Son, M.; Zheng, B.; Chang, J. J.; Jing, L. Z.; Huang, K. W.; Kim, D.; Chi, C. Y. Pro-aromatic bisphenaleno-thieno[3,2-b]thiophene versus anti-aromatic bisindeno-thieno[3,2-b]thiophene: Different ground-state properties and applications in field-effect transistors. Chem. Commun. 2015, 51, 13178–13180.
Joseph, V.; Yu, C. H.; Lin, C. C.; Lien, W. C.; Tsai, H. C.; Chen, C. S.; Torimtubun, A. A. A.; Velusamy, A.; Huang, P. Y.; Lee, G. H. et al. Quinoidal thioalkyl-substituted bithiophene small molecule semiconductors for n-type organic field effect transistors. J. Mater. Chem. C 2020, 8, 15450–15458.
Wang, C.; Ren, X. C.; Xu, C. H.; Fu, B. B.; Wang, R. H.; Zhang, X. T.; Li, R. J.; Li, H. X.; Dong, H. L.; Zhen, Y. G. et al. N-type 2D organic single crystals for high-performance organic field-effect transistors and near-infrared phototransistors. Adv. Mater. 2018, 30, 1706260.
Vegiraju, S.; Torimtubun, A. A. A.; Lin, P. S.; Tsai, H. C.; Lien, W. C.; Chen, C. S.; He, G. Y.; Lin, C. Y.; Zheng, D.; Huang, Y. F. et al. Solution-processable quinoidal dithioalkylterthiophene-based small molecules pseudo-pentathienoacenes via an intramolecular S···S lock for high-performance n-type organic field-effect transistors. ACS Appl. Mater. Interfaces 2020, 12, 25081–25091.
Zhang, C.; Zang, Y. P.; Gann, E.; McNeill, C. R.; Zhu, X. Z.; Di, C. A.; Zhu, D. B. Two-dimensional π-expanded quinoidal terthiophenes terminated with dicyanomethylenes as n-type semiconductors for high-performance organic thin-film transistors. J. Am. Chem. Soc. 2014, 136, 16176–16184.
Zhang, C.; Zang, Y. P.; Zhang, F. J.; Diao, Y.; McNeill, C. R.; Di, C. A.; Zhu, X. Z.; Zhu, D. B. Pursuing high-mobility n-type organic semiconductors by combination of “molecule-framework” and “side-chain” engineering. Adv. Mater. 2016, 28, 8456–8462.
Yuan, D. F.; Huang, D. Z.; Zhang, C.; Zou, Y.; Di, C. A.; Zhu, X. Z.; Zhu, D. B. Efficient solution-processed n-type small-molecule thermoelectric materials achieved by precisely regulating energy level of organic dopants. ACS Appl. Mater. Interfaces 2017, 9, 28795–28801.
Yang, K.; Zhang, X. H.; Harbuzaru, A.; Wang, L.; Wang, Y.; Koh, C.; Guo, H.; Shi, Y. Q.; Chen, J. H.; Sun, H. L. et al. Stable organic Diradicals based on fused quinoidal oligothiophene imides with high electrical conductivity. J. Am. Chem. Soc. 2020, 142, 4329–4340.
Wang, D. L.; Qiao, X. L.; Ouyang, G. C.; Wu, H. Z.; Li, H. X. Fluorine-substituted quinoidal thiophene with a F–H hydrogen bond locked conformation for high-performance n-channel organic transistors. Chem. Commun. 2019, 55, 6253–6256.
Wu, H. Z.; Wang, Y.; Qiao, X. L.; Wang, D. L.; Yang, X. D.; Li, H. X. Pyrrolo[3,2-b]pyrrole-based quinoidal compounds for high performance n-channel organic field-effect transistor. Chem. Mater. 2018, 30, 6992–6997.
Shang, W. S.; Han, G. C.; Fan, Q. R.; Yu, X. B.; Liu, D. S.; Li, C.; Zhang, X. S.; Yi, Y. P.; Zhang, G. X.; Zhang, D. Q. An extended quinoid molecule based on bis(thiophene-diketopyrrolopyrrole) with balanced ambipolar semiconducting properties and strong near-infrared absorption. Org. Chem. Front. 2023, 10, 632–639.
Ren, L. B.; Yuan, D. F.; Zhu, X. Z. Design of a quinoidal thieno[3,4-b]thiophene-diketopyrrolopyrrole-based small molecule as n-type semiconductor. Chem. Asian J. 2019, 14, 1717–1722.
Lin, Z. H.; Chen, L.; Xu, Q.; Shao, G. W.; Zeng, Z. Y.; Wu, D.; Xia, J. L. Tuning biradical character to enable high and balanced ambipolar charge transport in a quinoidal π-system. Org. Lett. 2020, 22, 2553–2558.
Yin, X. J.; Zhong, F.; Chen, Z. X.; Gao, C. M.; Xie, G. H.; Wang, L.; Yang, C. L. Manipulating the doping level via host-dopant synergism towards high performance n-type thermoelectric composites. Chem. Eng. J. 2020, 382, 122817.
Huang, L. F.; Eedugurala, N.; Benasco, A.; Zhang, S.; Mayer, K. S.; Adams, D. J.; Fowler, B.; Lockart, M. M.; Saghayezhian, M.; Tahir, H. et al. Open-shell donor–acceptor conjugated polymers with high electrical conductivity. Adv. Funct. Mater. 2020, 30, 1909805.
London, A. E.; Chen, H.; Sabuj, M. A.; Tropp, J.; Saghayezhian, M.; Eedugurala, N.; Zhang, B. A.; Liu, Y.; Gu, X.; Wong, B. M. et al. A high-spin ground-state donor–acceptor conjugated polymer. Sci. Adv. 2019, 5, eaav2336.
Joo, Y.; Huang, L. F.; Eedugurala, N.; London, A. E.; Kumar, A.; Wong, B. M.; Boudouris, B. W.; Azoulay, J. D. Thermoelectric performance of an open-shell donor–acceptor conjugated polymer doped with a radical-containing small molecule. Macromolecules 2018, 51, 3886–3894.
Steelman, M. E.; Adams, D. J.; Mayer, K. S.; Mahalingavelar, P.; Liu, C. T.; Eedugurala, N.; Lockart, M.; Wang, Y. F.; Gu, X. D.; Bowman, M. K. et al. Magnetic ordering in a high-spin donor–acceptor conjugated polymer. Adv. Mater. 2022, 34, 2206161.
Adams, D. J.; Mayer, K. S.; Steelman, M.; Azoulay, J. D. Magnetic characterization of open-shell donor–acceptor conjugated polymers. J. Phys. Chem. C 2022, 126, 5701–5710.
Mayer, K. S.; Adams, D. J.; Eedugurala, N.; Lockart, M. M.; Mahalingavelar, P.; Huang, L. F.; Galuska, L. A.; King, E. R.; Gu, X. D.; Bowman, M. K. et al. Topology and ground state control in open-shell donor–acceptor conjugated polymers. Cell Rep. Phys. Sci. 2021, 2, 100467.
Tam, T. L. D.; Wu, G.; Chien, S. W.; Lim, S. F. V.; Yang, S. W.; Xu, J. W. High spin pro-quinoid benzo[1,2-c;4,5-c']bisthiadiazole conjugated polymers for high-performance solution-processable polymer thermoelectrics. ACS Mater. Lett. 2020, 2, 147–152.
Fan, J.; Yuen, J. D.; Cui, W. B.; Seifter, J.; Mohebbi, A. R.; Wang, M. F.; Zhou, H. Q.; Heeger, A.; Wudl, F. High-hole-mobility field-effect transistors based on Co-benzobisthiadiazole-quaterthiophene. Adv. Mater. 2012, 24, 6164–6168.
Tam, T. L. D.; Ng, C. K.; Lim, S. L.; Yildirim, E.; Ko, J.; Leong, W. L.; Yang, S. W.; Xu, J. W. Proquinoidal-conjugated polymer as an effective strategy for the enhancement of electrical conductivity and thermoelectric properties. Chem. Mater. 2019, 31, 8543–8550.
Chen, X. X.; Li, J. T.; Fang, Y. H.; Deng, X. Y.; Wang, X. Q.; Liu, G. C.; Wang, Y. F.; Gu, X. D.; Jiang, S. D.; Lei, T. High-mobility semiconducting polymers with different spin ground states. Nat. Commun. 2022, 13, 2258.
Yuan, D. F.; Liu, L. Y.; Jiao, X. C.; Zou, Y.; McNeill, C. R.; Xu, W.; Zhu, X. Z.; Zhu, D. B. Quinoid-resonant conducting polymers achieve high electrical conductivity over 4000 S·cm−1 for thermoelectrics. Adv. Sci. 2018, 5, 1800947.
Hwang, H. S.; Kim, Y.; Kang, M. J.; Lee, M. H.; Heo, Y. J.; Kim, D. Y. A conjugated polymer with high planarity and extended π-electron delocalization via a quinoid structure prepared by short synthetic steps. Polym. Chem. 2017, 8, 361–365.
Kim, Y.; Hwang, H.; Kim, N. K.; Hwang, K.; Park, J. J.; Shin, G. I.; Kim, D. Y. π-conjugated polymers incorporating a novel planar quinoid building block with extended delocalization and high charge carrier mobility. Adv. Mater. 2018, 30, 1706557.
Deng, Y. F.; Quinn, J.; Sun, B.; He, Y. H.; Ellard, J.; Li, Y. N. Thiophene-S,S-dioxidized indophenine (IDTO) based donor–acceptor polymers for n-channel organic thin film transistors. RSC Adv. 2016, 6, 34849–34854.
Guo, K.; Wu, B. T.; Jiang, Y.; Wang, Z. L.; Liang, Z. Q.; Li, Y. N.; Deng, Y. F.; Geng, Y. H. Synthesis of an isomerically pure thienoquinoid for unipolar n-type conjugated polymers: Effect of backbone curvature on charge transport performance. J. Mater. Chem. C 2019, 7, 10352–10359.
Hwang, K.; Lee, M. H.; Kim, J.; Kim, Y. J.; Kim, Y.; Hwang, H.; Kim, I. B.; Kim, D. Y. 3,4-ethylenedioxythiophene-based isomer-free quinoidal building block and conjugated polymers for organic field-effect transistors. Macromolecules 2020, 53, 1977–1987.
Sun, Y. L.; Zhang, Y. P.; Ran, Y.; Shi, L. X.; Zhang, Q. S.; Chen, J. Y.; Li, Q. Y.; Guo, Y. L.; Liu, Y. Q. Methoxylation of quinoidal bithiophene as a single regioisomer building block for narrow-bandgap conjugated polymers and high-performance organic field-effect transistors. J. Mater. Chem. C 2020, 8, 15168–15174.
Rumer, J. W.; Levick, M.; Dai, S. Y.; Rossbauer, S.; Huang, Z. G.; Biniek, L.; Anthopoulos, T. D.; Durrant, J. R.; Procter, D. J.; McCulloch, I. BPTs: Thiophene-flanked benzodipyrrolidone conjugated polymers for ambipolar organic transistors. Chem. Commun. 2013, 49, 4465–4467.
Cui, W. B.; Wudl, F. Dithienylbenzodipyrrolidone: New acceptor for donor–acceptor low band gap polymers. Macromolecules 2013, 46, 7232–7238.
Zhang, H. C.; Zhang, S.; Mao, Y. F.; Liu, K. W.; Chen, Y. M.; Jiang, Z.; Strzalka, J.; Yang, W. J.; Wang, C. L.; Zhu, Y. Naphthodipyrrolidone (NDP) based conjugated polymers with high electron mobility and ambipolar transport properties. Polym. Chem. 2017, 8, 3255–3260.
Du, T.; Liu, Y. Y.; Wang, C.; Deng, Y. F.; Geng, Y. H. N-type conjugated polymers based on an indandione-terminated quinoidal building block. Macromolecules 2022, 55, 5975–5984.
Zhao, X. X.; Cai, H. J.; Deng, Y. F.; Jiang, Y.; Wang, Z. L.; Shi, Y. B.; Han, Y.; Geng, Y. H. Low-band gap conjugated polymers with strong absorption in the second near-infrared region based on diketopyrrolopyrrole-containing quinoidal units. Macromolecules 2021, 54, 3498–3506.
Tomlinson, E. P.; Mukherjee, S.; Boudouris, B. W. Enhancing polymer thermoelectric performance using radical dopants. Org. Electron. 2017, 51, 243–248.
Yuan, D. F.; Guo, Y.; Zeng, Y.; Fan, Q. R.; Wang, J. J.; Yi, Y. P.; Zhu, X. Z. Air-stable n-type thermoelectric materials enabled by organic diradicaloids. Angew. Chem., Int. Ed. 2019, 58, 4958–4962.
Yuan, D. F.; Huang, D. Z.; Rivero, S. M.; Carreras, A.; Zhang, C.; Zou, Y.; Jiao, X. C.; McNeill, C. R.; Zhu, X. Z.; Di, C. A. et al. Cholesteric aggregation at the quinoidal-to-diradical border enabled stable n-doped conductor. Chem 2019, 5, 964–976.
Yuan, D. F. Stable n-doped conductors enabled by organic Diradicals. Chem 2019, 5, 744–745.
Yuan, B. K.; Li, C.; Zhao, Y.; Gröning, O.; Zhou, X. Y.; Zhang, P. F.; Guan, D. D.; Li, Y. Y.; Zheng, H.; Liu, C. H. et al. Resolving quinoid structure in poly(para-phenylene) chains. J. Am. Chem. Soc. 2020, 142, 10034–10041.
Tam, T. L. D.; Moudgil, A.; Teh, W. J.; Wong, Z. M.; Handoko, A. D.; Chien, S. W.; Yang, S. W.; Yeo, B. S.; Leong, W. L.; Xu, J. W. Polaron delocalization dependence of the conductivity and the seebeck coefficient in doped conjugated polymers. J. Phys. Chem. B 2022, 126, 2073–2085.
Zhang, Y.; Zheng, Y. H.; Zhou, H. Q.; Miao, M. S.; Wudl, F.; Nguyen, T. Q. Temperature tunable self-doping in stable diradicaloid thin-film devices. Adv. Mater. 2015, 27, 7412–7419.
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