TY - JOUR
T1 - Impact of Molecular Weight on Molecular Doping Efficiency of Conjugated Polymers and Resulting Thermoelectric Performances
AU - Yoon, Sang Eun
AU - Kim, Bomi
AU - Chun, So Yeon
AU - Lee, Sang Yeon
AU - Jeon, Dohyeon
AU - Kim, Minju
AU - Lee, Solin
AU - Seo, Bo Eun
AU - Choi, Kang Suh
AU - Kim, Felix Sunjoo
AU - Kim, Taekyeong
AU - Seo, Hyungtak
AU - Kwak, Kyungwon
AU - Kim, Jong H.
AU - Kim, Bong Soo
N1 - Funding Information:
S.E.Y and B.K. contributed equally to this work. This research was supported by NRF grants funded by the Korea government (MSIT) (NRF‐2021R1A2C1007304, NRF‐2020R1A2C2014151, NRF‐2018R1A5A1025594, and NRF‐2020R1A5A1019141). This research was also supported by a grant from Priority Research Centers Program (NRF‐2019R1A6A1A11051471) funded by the National Research Foundation of Korea (NRF). GIWAXS experiments at PLS‐II 6D UNIST‐PAL beamline were supported in part by MEST, POSTECH, and UNIST UCRF.
Funding Information:
S.E.Y and B.K. contributed equally to this work. This research was supported by NRF grants funded by the Korea government (MSIT) (NRF-2021R1A2C1007304, NRF-2020R1A2C2014151, NRF-2018R1A5A1025594, and NRF-2020R1A5A1019141). This research was also supported by a grant from Priority Research Centers Program (NRF-2019R1A6A1A11051471) funded by the National Research Foundation of Korea (NRF). GIWAXS experiments at PLS-II 6D UNIST-PAL beamline were supported in part by MEST, POSTECH, and UNIST UCRF.
Publisher Copyright:
© 2022 Wiley-VCH GmbH.
PY - 2022/8/8
Y1 - 2022/8/8
N2 - The effect of molecular weight of a series of conjugated polymers (CPs) on the doping efficiency, electrical conductivity, and related thermoelectric properties of doped CPs is studied. Low (L), medium (M), and high (H) molecular weight batches of PDFD-T polymers, based on difluorobenzothiadiazole and dithienosilole moieties, are synthesized and denoted as PDFD-T(L), PDFD-T(M), and PDFD-T(H), respectively. Furthermore, to compare the effects of different donor moieties, donor units of PDFD-T(L) are structurally modified from thiophene to thienothiophene (TT) and dithienothiophene (DTT), denoted as PDFD-TT(L) and PDFD-DTT(L), respectively. After doping the CPs with FeCl3, d-PDFD-T(H) exhibits an electrical conductivity of 402.9 S cm−1, which is significantly higher than those of d-PDFD-T(L), d-PDFD-T(M), d-PDFD-TT(L), and d-PDFD-DTT(L). The highest power factor of 101.1 µW m−1 K−2 is achieved through organic thermoelectric devices fabricated using PDFD-T(H). Through various characterizations, it is demonstrated that CPs with a high molecular weight tend to have a high carrier mobility while maintaining their original crystallinity and good charge transport pathways even after doping. Therefore, it is suggested that optimizing the molecular weight of CPs is an essential strategy for maximal power generation from their doped CP films.
AB - The effect of molecular weight of a series of conjugated polymers (CPs) on the doping efficiency, electrical conductivity, and related thermoelectric properties of doped CPs is studied. Low (L), medium (M), and high (H) molecular weight batches of PDFD-T polymers, based on difluorobenzothiadiazole and dithienosilole moieties, are synthesized and denoted as PDFD-T(L), PDFD-T(M), and PDFD-T(H), respectively. Furthermore, to compare the effects of different donor moieties, donor units of PDFD-T(L) are structurally modified from thiophene to thienothiophene (TT) and dithienothiophene (DTT), denoted as PDFD-TT(L) and PDFD-DTT(L), respectively. After doping the CPs with FeCl3, d-PDFD-T(H) exhibits an electrical conductivity of 402.9 S cm−1, which is significantly higher than those of d-PDFD-T(L), d-PDFD-T(M), d-PDFD-TT(L), and d-PDFD-DTT(L). The highest power factor of 101.1 µW m−1 K−2 is achieved through organic thermoelectric devices fabricated using PDFD-T(H). Through various characterizations, it is demonstrated that CPs with a high molecular weight tend to have a high carrier mobility while maintaining their original crystallinity and good charge transport pathways even after doping. Therefore, it is suggested that optimizing the molecular weight of CPs is an essential strategy for maximal power generation from their doped CP films.
KW - conjugated polymers
KW - electrical conductivity
KW - molecular dopants
KW - molecular weight
KW - thermoelectric effect
UR - http://www.scopus.com/inward/record.url?scp=85130446888&partnerID=8YFLogxK
U2 - 10.1002/adfm.202202929
DO - 10.1002/adfm.202202929
M3 - Article
AN - SCOPUS:85130446888
SN - 1616-301X
VL - 32
JO - Advanced Functional Materials
JF - Advanced Functional Materials
IS - 32
M1 - 2202929
ER -