Anion-assisted Yb3+ and Mn2+ doping of 0D and 2D lead halide perovskite nanostructures

Abstract

Currently, lead halide perovskite nanostructures are an essential platform for designing new optical materials with required functionalities. Photoluminescence (PL) wavelength tuning is an important tool for targeted applications of optical materials in photonics and optoelectronics. Doping with lanthanides allows shifting the PL band into the near-infrared spectral region. Although post-synthetic doping is a versatile strategy that uses high-quality nanostructures with a given morphology, the approach is poorly developed for lanthanide-doped perovskites. Here, we propose anion-assisted cation doping in a nonpolar solvent at room temperature as a universal method to create multiple-band emitting lead halide perovskite nanostructures. Applying precursors MCl_x (M = Yb, Mn) to the pre-synthesized perovskite nanostructures, we have obtained near-infrared emitting Yb³⁺-doped CsPbCl_xBr_3−x and FAPbCl_xBr_3−x nanocrystals and nanoplatelets, as well as double-wavelength emitting Mn²⁺-doped, and triple-wavelength emitting Mn²⁺–Yb³⁺ co-doped CsPbCl_xBr_3−x nanoplatelets. In all cases, doping is carried out due to simultaneous introduction of new cations and anions; the process dynamics depends on the type of doping ion, and the composition and morphology of the pristine perovskite nanomaterial. The versatility of the doping approach proposed opens up new ways for creating perovskite nanostructures with unique optical properties.