Simulation-assisted optimization and upscaling of organic photovoltaics: From small cells to large-area modules

In this work, we present the systematic upscaling of fully solution-processed poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo[1,2-b:4,5-b′]dithiophene))-alt-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo[1′,2′-c:4′,5′-c′] dithiophene-4,8-dione)] (PM6):2,2′-((2Z,2′Z)-((12,13-bis(2-butyloctyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4e]thieno [2″,3″:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (Y6-C12):[6,6]-phenyl-C61-butyric acid methyl ester (PC 61 BM) devices processed in ambient air from non-halogenated solvents by a scalable blade-coating process. The developed layer stack contains a silver nanowire top electrode and provides excellent light stability, with 88.4% power conversion efficiency (PCE) retention after 2,530 h of illumination and an extrapolated T 80 lifetime of >20,000 h. Computer simulation-assisted stack and layout optimizations lead to 1 cm² champion cell efficiencies of 15.9% with evaporated silver (opaque) and 11.5% with silver nanowires (semitransparent). Finite element method (FEM) simulations were used to optimize the layout of the large-area modules by minimizing inevitable losses caused by the electrodes' resistivity and inactive interconnect areas. Finally, fully printed, semitransparent modules with a champion PCE of 9.8% on >200 cm² (10.3% on active area) are demonstrated.