Controlling the grain size of the organic–inorganic perovskite thin films using thiourea additives now crossing 2 μm size with >20% power conversion efficiency.
Two non-fullerene small molecule acceptors, NT-4F and NT-4Cl, were designed and synthesized. Power conversion efficiencies of 11.44% and 14.55% were achieved for NT-4Cl-based binary and ternary devices, respectively.