A halogenated volatile additive strategy for regulating crystallization kinetics and enabling 20.40% efficiency polymer solar cells with low non-radiative recombination energy loss

Increasing the weight of halogen atoms of additives results in balanced crystallization and optimal morphology with suppressed energy disorder, realizing 20.40% efficiency with a Δ E non-rad of 0.189 eV and E loss of 0.500 eV in polymer solar cells.