TY - JOUR
T1 - Semi-planar-semi-twisted selenophen-containing narrow bandgap small molecules for efficient polymer solar cells
AU - Wang, Weiping
AU - Zhao, Baofeng
AU - Liu, Jiahao
AU - Wang, Liuchang
AU - Zhao, Tianyi
AU - Cong, Zhiyuan
AU - Wu, Haimei
AU - Yang, Zhi
AU - Meng, Zihui
AU - Gao, Chao
N1 - Publisher Copyright:
© 2025 Elsevier B.V.
PY - 2025/6
Y1 - 2025/6
N2 - Polymer solar cells (PSCs) containing small molecule electron acceptors (SMAs) with twisted backbones offer many advantages over flat molecules, including the ability to move molecular energy levels, enhanced charge extraction properties, higher extinction coefficients, longer carrier lifetimes, and lower recombination rates. Collectively, these advantages contribute to the power conversion efficiency (PCE) of PSCs. However, the restricted absorption spectra of twisted SMAs present a challenge to further performance improvement. To address this issue, three acceptor-π-donor-π’-acceptor-type SMAs with indacenodiselenophene (IDSe) segment as the electron-giving unit and halogenated end groups were designed and synthesized. Taking advantage of the strong electron donating ability of the IDSe fusing ring core and the introduced isomerized π bridged segments, all SMAs exhibit red-shifted absorption in the near-infrared region and successfully generate a semi-planar semi-twisted backbone. When blended with J52, the devices of the two halogenated SMAs (h-IDSe-4F and h-IDSe-4Cl) showed preferable exciton dissociations, low recombination rates, balanced and high charge mobilities, leading to high efficiencies of 9.33 % and 9.03 %, higher than the 5.07 % of the h-IDSe-based device. This work demonstrates that tuning the planarity of the conjugated backbone, fine-tuning the core unit, and halogenation substitutions in the end groups have a significant impact on regulating the light-harvesting and performance of organic photovoltaic devices.
AB - Polymer solar cells (PSCs) containing small molecule electron acceptors (SMAs) with twisted backbones offer many advantages over flat molecules, including the ability to move molecular energy levels, enhanced charge extraction properties, higher extinction coefficients, longer carrier lifetimes, and lower recombination rates. Collectively, these advantages contribute to the power conversion efficiency (PCE) of PSCs. However, the restricted absorption spectra of twisted SMAs present a challenge to further performance improvement. To address this issue, three acceptor-π-donor-π’-acceptor-type SMAs with indacenodiselenophene (IDSe) segment as the electron-giving unit and halogenated end groups were designed and synthesized. Taking advantage of the strong electron donating ability of the IDSe fusing ring core and the introduced isomerized π bridged segments, all SMAs exhibit red-shifted absorption in the near-infrared region and successfully generate a semi-planar semi-twisted backbone. When blended with J52, the devices of the two halogenated SMAs (h-IDSe-4F and h-IDSe-4Cl) showed preferable exciton dissociations, low recombination rates, balanced and high charge mobilities, leading to high efficiencies of 9.33 % and 9.03 %, higher than the 5.07 % of the h-IDSe-based device. This work demonstrates that tuning the planarity of the conjugated backbone, fine-tuning the core unit, and halogenation substitutions in the end groups have a significant impact on regulating the light-harvesting and performance of organic photovoltaic devices.
KW - Indacenodiselenophene
KW - Polymer solar cells
KW - Power conversion efficiency
KW - Semi-planar-semi-twisted molecules
KW - Small molecule acceptors
UR - http://www.scopus.com/inward/record.url?scp=86000727055&partnerID=8YFLogxK
U2 - 10.1016/j.synthmet.2025.117864
DO - 10.1016/j.synthmet.2025.117864
M3 - Article
AN - SCOPUS:86000727055
SN - 0379-6779
VL - 312
JO - Synthetic Metals
JF - Synthetic Metals
M1 - 117864
ER -