Effect of halogen/chalcogen substitution on the dielectric constant of asymmetric acceptor alloy to improve the efficiency and stability of inverted organic photovoltaics.

ABSTRACT: The dielectric constant (ε _r) of non-fullerene acceptors is a key parameter in organic solar cells, significantly influencing exciton dissociation efficiency and charge recombination dynamics. Substituting bromine, characterized by moderate electronegativity and high polarizability, at the o-benzodipyrrole core of acceptors effectively modulates their optical properties, molecular packing, and dielectric constants. The asymmetric monobrominated CBrB-Cl acceptor exhibits a more red-shifted absorption spectrum, enhanced crystallinity, and a higher ε _r of 3.92, contributing to a high efficiency of 17.69% in the inverted PM6:CBrB-Cl device. Further, a selenium-incorporated CB-Se acceptor was selected to form a well-matched dual asymmetric acceptor all

SUBMITTER: Wang YB 

PROVIDER: S-EPMC12403024 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature