Processing Strategies for an Organic Photovoltaic Module with over 10% Efficiency

A series of readily accessible and scalable benzo[1,2-b:4,5-b']dithiophene (BDT)-2,5-dithienyl-thieno[3,4-c]pyrrole-4,6-dione (TPD-T2)-based donor polymers are utilized in organic photovoltaic (OPV) cells blended with the nonfullerene acceptor IT-4F. All polymers readily dissolve in chlorine-free solvents such as xylene, and the corresponding photoactive blend films can be processed in ambient from this solvent to fabricate cells with power conversion efficiencies (PCEs) >12%-14%. Furthermore, the blend processing and OPV metrics are remarkably insensitive to the processing methodology (spin coating versus blade coating), processing solvent, polymer molecular mass and dispersity index, and the results were rationalized by UV-vis, PL, fsTA, AFM, TEM, GIWAXS, and SCLC measurements. These properties enable the first OPV modules, processed in ambient from a benign solvent, with a certified PCE of 10.1% for an area of 20.4 cm(2) and >7% after light soaking. The same module also delivers a power of similar to 40 mu W/cm(2) (PCE similar to 22%) under indoor lighting.