Photovoltage enhancement of M-series acceptor-based polymer solar cells and minimodules through the modulation of charge-transfer states.

ABSTRACT: Side-chain fluorination can enhance the backbone organization and carrier mobility of non-fullerene acceptors (NFAs) but it often reduces their photovoltage due to the resulting deeper-lying lowest unoccupied molecular orbital (LUMO) levels. Herein, we present a strategy to regulate the LUMO levels of two NFAs, MC9F5 and MC7F5, by repositioning the highly electronegative -C₂F₅ moieties on the side chains. This approach mitigates the impact of fluorination on the energy levels, thereby improving the photovoltage and overall device performance. By incorporating 10,10,11,11,11-pentafluoro-2-(8,8,9,9,9-pentafluorononyl)undecyl side chains, the -C₂F₅ moieties are positioned away from the conjugated backbone of MC9F5, resulting in an elevated LUMO leve

SUBMITTER: Xing K 

PROVIDER: S-EPMC11970251 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature