Low?Cost Dopant?Free Carbazole Enamine Hole?Transporting Materials for Thermally Stable Perovskite Solar Cells

Perovskite solar cells deliver high efficiencies, but are often made from high-cost bespoke chemicals, such as the archetypical hole-conductor, 2,2?,7,7?-tetrakis(N,N-di-p-methoxy-phenylamine)-9-9?-spirobifluorene (spiro-OMeTAD). Herein, new charge-transporting carbazole-based enamine molecules reported. The hole conductors do not require chemical oxidation to reach power conversion efficiencies (PCEs) when employed in n-type-intrinsic-p-type perovskite cells; thus, reducing risk of moisture degrading layer through hydrophilicity oxidizing additives that typically used with conventional conductors. Devices these undoped enamines achieve comparable PCEs those employing doped spiro-OMeTAD, and greatly enhanced stability under 85 °C thermal aging; maintaining 83% their peak efficiency after 1000 h, compared spiro-OMeTAD-based devices degrade 26% PCE within 24 h. Furthermore, can be synthesized without use organometallic catalysts complicated purification techniques, lowering material cost by one order magnitude spiro-OMeTAD. As a result, we calculate overall manufacturing costs future photovoltaic (PV) modules reduced, making levelized electricity competitive silicon PV modules.