Terminal Cyano-Functionalized Fused Bithiophene Imide Dimer- Based n-Type Small Molecular Semiconductors: Synthesis, Structure-Property Correlations, and Thermoelectric Performances

Wang, Dong2,3; Li, Jianfeng3; Yang, Kun1; Wang, Yimei3; Jeong, Sang Young4; Chen, Zhicai3; Liao, Qiaogan3; Li, Bangbang3; Woo, Han Young4; Deng, Xianyu2; Guo, Xugang3

2023-02-22

10.1021/acsami.2c20489

ACS Applied Materials & Interfaces   Impact Factor & Quartile

1944-8244

1944-8252

n-Doped small molecular organic thermoelectric materials (OTMs) hold advantages of high Seebeck coefficient and better performance reproducibility over their polymeric analogues; however, high-performance n-type small molecular OTMs are severely lacking. We report here a class of small molecular OTMs based on terminal cyanation of a bithiophene imide-based ladder -type heteroarene BTI2. It was found that the cyanation could effectively lower the lowest unoccupied molecular orbital (LUMO) level from -2.90 eV (BTI2) to -4.14 eV (BTI2-4CN) and thus lead to significantly improved n-doping efficiency. Additionally, terminal cyano-functionalization can maintain the close packing and efficient intermolecular charge transfer between these cyanated molecules, thus yielding high electron mobilities of up to 0.40 cm2 V-1 s-1. Benefiting from its low LUMO-enabled efficient n-doping and high electron mobility, an encouraging n-type electrical conductivity of 0.43 S cm-1 and power factor (PF) of 6.34 mu W m-1 K-2 were achieved for tetracyanated BTI2-4CN, significantly outperforming those of its noncynated BTI2 (<10-7 S cm-1, PF undetectable) and dicyanated BTI2-2CN (0.24 S cm-1, 1.78 mu W m-1 K-2). These results suggest the great potential of the terminal cyanation strategy of ladder-type heteroarenes for developing high-performance small molecular OTMs.

organic thermoelectrics n-type organic semiconductors terminal cyanation bithiophene imide structure-property correlations

SCI

English

Corresponding

National Natural Science Foundation of China["52273171","21875055"] ; Guangdong Basic and Applied Basic Research Foundation[2019R1A6A1A11044070] ; China Post-doctoral Science Foundation[GXWD20201230155427003] ; National Research Foundation of Korea[22005133] ; Shenzhen Research Foundation Project[52173171] ; null[2022A1515010935] ; null[2021M701550]

Science & Technology - Other Topics ; Materials Science

Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary

WOS:000936470300001

AMER CHEMICAL SOC

Web of Science

1.Hunan Univ, Coll Chem & Chem Engn, State Key Lab Chemo Biosensing & Chemometr, Changsha 410082, Peoples R China
2.Harbin Inst Technol, Sch Mat Sci & Engn, Shenzhen Key Lab Adv Mat, Shenzhen 518055, Guangdong, Peoples R China
3.Southern Univ Sci & Technol SUSTech, Dept Mat Sci & Engn, Shenzhen 518055, Guangdong, Peoples R China
4.Korea Univ, Res Inst Nat Sci, Dept Chem, Seoul 02841, South Korea

Wang, Dong,Li, Jianfeng,Yang, Kun,et al. Terminal Cyano-Functionalized Fused Bithiophene Imide Dimer- Based n-Type Small Molecular Semiconductors: Synthesis, Structure-Property Correlations, and Thermoelectric Performances[J]. ACS Applied Materials & Interfaces,2023,15(7).

Wang, Dong.,Li, Jianfeng.,Yang, Kun.,Wang, Yimei.,Jeong, Sang Young.,...&Guo, Xugang.(2023).Terminal Cyano-Functionalized Fused Bithiophene Imide Dimer- Based n-Type Small Molecular Semiconductors: Synthesis, Structure-Property Correlations, and Thermoelectric Performances.ACS Applied Materials & Interfaces,15(7).

Wang, Dong,et al."Terminal Cyano-Functionalized Fused Bithiophene Imide Dimer- Based n-Type Small Molecular Semiconductors: Synthesis, Structure-Property Correlations, and Thermoelectric Performances".ACS Applied Materials & Interfaces 15.7(2023).