Self-trapped-induced energy funneling and broadband emission in the Mn2+ doped two-dimensional perovskite

The electronic structure modulations by metal cation doping and organic ligands modification are aroused great interests in perovskite community for spectrum tailoring and quantum yield (QY) enhancement. Herein, we synthesized the two-dimensional (2D) lead bromide perovskite with cyclohexenylethylamine as the organic ammonium ligands and divalent manganese as the doping ions by the combination of facile solution processes and low temperature solid-state method. Thanks to the synergy effects of the steric-hindrance induced self-trapped exciton (STE) by A-site engineering and the elevation of cascaded energy funneling among the FE, STE and the 4T1→6A1 transition of Mn2+. The emission spectrum of the Mn2+ doped 2D perovskite simultaneously covers both the blue and orange range with a QY of 47.01%, where the value is about twelve times of that of the un-doped one at room temperature. Our results indicate that the utilizing of soft organic ammonium and Mn2+ doping in 2D perovskite could not only adjust the energy level states and improve the QY remarkably, but also explore new opportunities in warm-white LEDs and other applications.