TY - JOUR
T1 - Backbone Configuration and Electronic Property Tuning of Imide-Functionalized Ladder-Type Heteroarenes-Based Polymer Acceptors for Efficient All-Polymer Solar Cells
AU - Liu, Bin
AU - Wang, Yingfeng
AU - Sun, Huiliang
AU - Gámez-Valenzuela, Sergio
AU - Yan, Zhenglong
AU - Feng, Kui
AU - Uddin, Mohammad Afsar
AU - Koh, Changwoo
AU - Zhou, Xin
AU - López Navarrete, Juan Teodomiro
AU - Ruiz Delgado, María Carmen
AU - Meng, Hong
AU - Niu, Li
AU - Woo, Han Young
AU - Ponce Ortiz, Rocío
AU - Guo, Xugang
N1 - Publisher Copyright:
© 2022 Wiley-VCH GmbH
PY - 2022
Y1 - 2022
N2 - Electron-deficient ladder-type π-conjugated systems are highly desired for constructing polymer acceptors due to their unique electronic properties. Herein, two series of polymer acceptors PBTIn-(F)T (n = 1–4) based on imide-functionalized ladder-type heteroarenes (BTIn) with tunable conjugation length are synthesized. Effects of their backbone configuration and electronic properties on film morphology and performance of all-polymer solar cells (all-PSCs) are systematically investigated through theoretical computation, Raman spectroscopy, grazing incidence wide-angle X-ray scattering, etc. It is found that the ladder-type heteroarene size extension and polymer backbone fluorination gradually lower the frontier molecular orbital energy levels, leading to progressive bandgap narrowing with more efficient exciton dissociation. Furthermore, the centrosymmetric and axisymmetric characteristics of BTIn result in distinct backbone configuration with varied self-aggregation and crystalline phases, hence determining the blend film morphology. The highest efficiencies in these two series are attained from PBTI3-T and PBTI3-FT with a curved backbone configuration. PBTI4-(F)T with further extended heteroarenes shows linear backbone, negatively affecting film morphology and efficiency. This study provides fundamental material structure-device performance correlations for ladder-type heteroarenes-based polymer acceptors for the first time and demonstrates that more extended ladder-type backbones do not necessarily improve the device performance, offering guidelines for designing polymer acceptors to maximize all-PSC performance.
AB - Electron-deficient ladder-type π-conjugated systems are highly desired for constructing polymer acceptors due to their unique electronic properties. Herein, two series of polymer acceptors PBTIn-(F)T (n = 1–4) based on imide-functionalized ladder-type heteroarenes (BTIn) with tunable conjugation length are synthesized. Effects of their backbone configuration and electronic properties on film morphology and performance of all-polymer solar cells (all-PSCs) are systematically investigated through theoretical computation, Raman spectroscopy, grazing incidence wide-angle X-ray scattering, etc. It is found that the ladder-type heteroarene size extension and polymer backbone fluorination gradually lower the frontier molecular orbital energy levels, leading to progressive bandgap narrowing with more efficient exciton dissociation. Furthermore, the centrosymmetric and axisymmetric characteristics of BTIn result in distinct backbone configuration with varied self-aggregation and crystalline phases, hence determining the blend film morphology. The highest efficiencies in these two series are attained from PBTI3-T and PBTI3-FT with a curved backbone configuration. PBTI4-(F)T with further extended heteroarenes shows linear backbone, negatively affecting film morphology and efficiency. This study provides fundamental material structure-device performance correlations for ladder-type heteroarenes-based polymer acceptors for the first time and demonstrates that more extended ladder-type backbones do not necessarily improve the device performance, offering guidelines for designing polymer acceptors to maximize all-PSC performance.
KW - all-polymer solar cells
KW - backbone configuration
KW - fluorination
KW - imide-functionalized ladder-type heteroarenes
KW - polymer acceptors
UR - http://www.scopus.com/inward/record.url?scp=85124720625&partnerID=8YFLogxK
U2 - 10.1002/adfm.202200065
DO - 10.1002/adfm.202200065
M3 - Article
AN - SCOPUS:85124720625
JO - Advanced Functional Materials
JF - Advanced Functional Materials
SN - 1616-301X
ER -