An All‐Solution Processed Recombination Layer with Mild Post‐Treatment Enabling Efficient Homo‐Tandem Non‐fullerene Organic Solar Cells

The first homo-tandem non-fullerene organic solar cell enabled by a novel recombination layer which only requires a very mild thermal annealing treatment is reported. The best efficiency achieved is 10.8% with a Voc over 2.1 V, which is the highest Voc for double-junction organic solar cells reported to date.