Photoluminescence quantum yield exceeding 80% in low dimensional perovskite thin-films via passivation control.

Quasi-2D perovskites with the BA : MA molar ratio equal to 3 : 3 show a remarkable PLQY exceeding 80%, thanks to the use of an electron donor as the passivating agent. These films have been applied in LEDs that exhibit high brightness exceeding 1000 cd m-2 and current efficiencies >3 cd A-1.