Charge photogeneration dynamics in non-fullerene polymer solar cells with fluorinated and non-fluorinated acceptors.
J Chem Phys
; 160(7)2024 Feb 21.
Article
en En
| MEDLINE
| ID: mdl-38364001
ABSTRACT
In this work, charge photogeneration and recombination processes of PM6IDIC-4F and PM6IDIC blend films were investigated by the steady-state and time-resolved spectroscopies, as well as the time-dependent density functional theory calculations. The peaks in absorption and photoluminescence (PL) spectra of IDIC and IDIC-4F solutions were assigned by combining the experiment and the simulation of UV-vis absorption and PL spectra. For neat acceptor films, the exciton diffusion length of neat IDIC and IDIC-4F films was estimated as â¼28.9 and â¼19.9 nm, respectively. For PM6-based blend films, we find that the fluorine substitution engineering on the IDIC acceptor material can increase the phase separate size of acceptor material in blend films, resulting in the reduction of dissociation efficiencies of acceptor excitons. In addition, we find that the charge recombination in PM6IDIC-4F is dominated by bimolecular recombination, in comparison to geminate type carrier recombination in PM6IDIC blend films. In addition, we find that thermal annealing treatment has a weak influence on carrier recombination but slightly reduces the exciton dissociation efficiency of acceptor in PM6IDIC blend films, leading to a slightly reduced power conversion efficiency of PM6IDIC solar cells. These results may shed light on the design of high-performance semiconductor molecules for application in solar cells.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
J Chem Phys
Año:
2024
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
Estados Unidos