Chlorine-Additives-Promoted Incorporation of Mn2+ Dopants in CsPbCl3 Perovskite Nanocrystals

Effective Mn2+ doping in CsPbCl3 lattice utilizing manganese acetate and trimethylchlorosilane is achieved via a one-pot hot-injection synthesis method. This strongly contrasts to the previously case, where only MnCl2 precursor was suitable for Mn2+ doping by considering the matching of bond dissociation energies between Mn-Cl and Pb-Cl. The Mn doping concentration and luminescence quantum yield are highly dependent on trimethylchlorosilane content. A new doping mechanism is proposed, where the incorporation of Mn2+ in CsPbCl3 is achieved via directly inserting [MnCl6]4- octahedrons into perovskite structure during the nucleation/growth processes instead of Mn-to-Pb cation exchange. Accordingly, increasing Cl- content in reaction solution indeed promotes the doping of other divalent transition metal ions such as Ni2+, Cu2+ and Zn2+ in CsPbCl3 and improve quantum yield of CsPbCl3 nanocrystals up to ~20% compared to the undoped counterparts (~1%).