Open-air, green-solvent processed organic solar cells with efficiency approaching 18% and exceptional stability

Abstract

The major challenges associated with bringing organic solar cells (OSCs) to the industrial market are to further improve power conversion efficiency (PCE), device stability, and green-solvent processability within an open-air (OA) environment. High-performance OSCs based on various active layers are realized by employing H75-2F among newly formulated cathode interfacial materials (CIMs), achieving not only a prominent PCE of up to 19.44% (certified 19.27%) under controlled processing conditions, but also exceptional device stabilities (e.g., shelf stress (T95 = 1000 h), thermal stress (T80 = 300 h), illumination (T80 = 500 h), and moisture exposure (T80 = 300 h)). Moreover, we also demonstrate an OA, green-solvent processed efficient H75-2F-based OSC with 17.78% PCE (certified 17.64%), representing the highest value for OA-processed OSCs in all-green systems. A comparative study of the CIM series reveals the underlying mechanisms correlated with macroscopic and microscopic morphologies, demonstrating the key features of simultaneous favored control for the fabrication of efficient OA-processed OSCs. H75-2F, a fluorinated cathode material, boosts organic solar cell efficiency, achieving 19.44% PCE in controlled conditions and 17.78% with open-air green-solvent processing, while offering strong thermal and moisture stability.