Environmentally Friendly Solvent‐Processed Organic Solar Cells that are Highly Efficient and Adaptable for the Blade‐Coating Method

TLDR

State‑of‑the‑art organic solar cells achieve over 13 % PCE, yet the solvents and laboratory coating methods commonly used are not scalable for practical production. The study aims to develop environmentally friendly solvent‑based solution‑coating methods for practical deployment of OSC technology. PBTA‑TF:IT‑M devices were fabricated with environmentally friendly solvents THF/IPA and o‑xylene/1‑phenylnaphthalene, achieving a 13.1 % PCE using spin‑coating. Blade‑coated non‑fullerene OSCs processed with THF/IPA reached 11.7 % PCE, and a 1.0 cm² blade‑coated device maintained 10.6 % PCE, underscoring their potential for large‑scale production.

Abstract

The power conversion efficiencies (PCEs) of state-of-the-art organic solar cells (OSCs) have increased to over 13%. However, the most commonly used solvents for making the solutions of photoactive materials and the coating methods used in laboratories are not adaptable for future practical production. Therefore, taking a solution-coating method with environmentally friendly processing solvents into consideration is critical for the practical utilization of OSC technology. In this study, a highly efficient PBTA-TF:IT-M-based device processed with environmentally friendly solvents, tetrahydrofuran/isopropyl alcohol (THF/IPA) and o-xylene/1-phenylnaphthalene, is fabricated; a high PCE of 13.1% can be achieved by adopting the spin-coating method, which is the top result for OSCs. More importantly, a blade-coated non-fullerene OSC processed with THF/IPA is demonstrated for the first time to obtain a promising PCE of 11.7%; even for the THF/IPA-processed large-area device (1.0 cm2 ) made by blade-coating, a PCE of 10.6% can still be maintained. These results are critical for the large-scale production of highly efficient OSCs in future studies.