Beyond the Mahan–Sofo best thermoelectric strategy: high thermoelectric performance from directional π-conjugation in two-dimensional poly(tetrathienoanthracene). Issue 8 (18th February 2020)

• Record Type: Journal Article
• Authors: Deng, Tianqi; Yong, Xue; Shi, Wen; Wong, Zicong Marvin; Wu, Gang; Pan, Hui; Wang, Jian-Sheng; Yang, Shuo-Wang
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 8(2020)
• Page Start: 4257
• Page End: 4262
• Publication Date: 2020-02-18
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9ta13886b
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : An intrinsic density-of-states peak leads to a high Seebeck coefficient of two-dimensional COF poly(tetrathienoanthracene) for thermoelectric applications. Abstract : Mahan and Sofo proved that the best thermoelectric performance could be found in materials with a sharp peak in the density-of-states (DOS) near the chemical potential, which may come from a localized electronic state. However, such a state usually results in a poor electrical conductivity. Therefore, such an idealized model leads to this question: is there a material which naturally possesses a narrow DOS peak near the band edge without a localized state? The answer is yes. From a number of covalent organic frameworks (COFs), we identified poly(tetrathienoanthracene) (PTTA), a purely organic 2D COF possessing such a DOS and subsequently achieves a significant thermoelectric performance with an enhanced Seebeck coefficient such that the peak n- and p-type power factors can reach up to 14.9 and 21.9 μW cm −1 K −2, respectively. This provided a feasible prototype of the Mahan–Sofo model and demonstrated for the first time that a purely organic 2D COF could exhibit high thermoelectric performance for functional applications.