Improved Device Performance and Stability in Organic Solar Cells by Morphology Control via Size‐Controlled Chevron‐Shaped Blades

Abstract

Organic solar cells (OSCs) have been studied widely as renewable energy resources for a few decades owing to their technological advantages, including low cost, light weight, flexibility, and the potential of large area printing. To upgrade the active layers of OSCs into an optimized form, a simple and straightforward strategy is demonstrated by introducing two types of size-controlled chevron (V)-shaped blades to delicately control PM6:Y6-based bulk heterojunction (BHJ) films under ambient conditions. A power conversion efficiency of 15.97% is achieved from the blade-coating methods using a small-sized V-shaped blade (V1), compared with 14.31% using a conventional flat blade (F). Using blade coating based on V1 improves the phase separation and molecular crystallinity in the active layer, which lead to decreased trap-assisted recombination and leakage current, finally increasing the short circuit current and fill factor. In addition, following these morphological changes in the optimal BHJ structure, the devices printed with V1 exhibit higher stability in the long-term shelf-life test (320 h storage in ambient conditions). Notably, strategy is a facile layer fabrication method that adopts V-shaped blades to achieve high device performance and stability for the practical use of large-area OSCs.