High-speed printing of a bulk-heterojunction architecture in organic solar cells films

Abstract

To facilitate the potential applications of organic solar cells (OSCs), the highly cost-effective processing fabrication of solar cells and modules is an important prerequisite. However, process development has received little attention and is rarely reported. Herein, we propose a polymeric self-doping strategy to fabricate high-performance bulk-heterojunction (BHJ)-type active layers with super-fast blade-coating speeds. We found that doping a small amount of PM6 with a relatively low molecular weight (namely PM6_L) into the PM6:Y6 system can remarkably improve the high-speed processability of the active layer without sacrificing its photovoltaic performance, supported by relevant morphological and physical measurements. The in situ analysis further illustrates the effects of PM6_L-doping on the molecular aggregation behaviors during the film-forming process at low and high blade-coating speeds. The universality of this PM6_L-doping strategy was confirmed in three other PM6-based BHJ-type OSCs. Importantly, the high-speed manufacturing of large-scale solar modules and their techno-economic analysis further highlight the merits of this strategy, thus driving the commercialization of the OSC technique forward.