Exciton-to-Dopant Energy Transfer in Mn-Doped Cesium\nLead Halide Perovskite Nanocrystals

Abstract

We\nreport the one-pot synthesis of colloidal Mn-doped cesium lead halide\n(CsPbX₃) perovskite nanocrystals and efficient intraparticle\nenergy transfer between the exciton and dopant ions resulting in intense\nsensitized Mn luminescence. Mn-doped CsPbCl₃ and CsPb­(Cl/Br)₃ nanocrystals maintained the same lattice structure and crystallinity\nas their undoped counterparts with nearly identical lattice parameters\nat ∼0.2% doping concentrations and no signature of phase separation.\nThe strong sensitized luminescence from d–d transition of Mn²⁺ ions upon band-edge excitation of the CsPbX₃ host\nis indicative of sufficiently strong exchange coupling between the\ncharge carriers of the host and dopant d electrons mediating the energy\ntransfer, essential for obtaining unique properties of magnetically\ndoped quantum dots. Highly homogeneous spectral characteristics of\nMn luminescence from an ensemble of Mn-doped CsPbX₃ nanocrystals\nand well-defined electron paramagnetic resonance spectra of Mn²⁺ in host CsPbX₃ nanocrystal lattices suggest relatively\nuniform doping sites, likely from substitutional doping at Pb²⁺. These observations indicate that CsPbX₃ nanocrystals,\npossessing many superior optical and electronic characteristics, can\nbe utilized as a new platform for magnetically doped quantum dots\nexpanding the range of optical, electronic, and magnetic functionality.