CsPb_xMn_1–xCl₃ Perovskite Quantum Dots with High Mn Substitution Ratio

Abstract

CsPbX (X = Cl, Br, I) perovskite quantum dots (QDs) are potential emitting materials for illumination and display applications, but toxic Pb is not environment- and user-friendly. In this work, we demonstrate the partial replacement of Pb with Mn through phosphine-free hot-injection preparation of CsPbMnCl QDs in colloidal solution. The Mn substitution ratio is up to 46%, and the as-prepared QDs maintain the tetragonal crystalline structure of the CsPbCl host. Meaningfully, Mn substitution greatly enhances the photoluminescence quantum yields of CsPbCl from 5 to 54%. The enhanced emission is attributed to the energy transfer of photoinduced excitons from the CsPbCl host to the doped Mn, which facilitates exciton recombination via a radiative pathway. The intensity and position of this Mn-related emission are also tunable by altering the experimental parameters, such as reaction temperature and the Pb-to-Mn feed ratio. A light-emitting diode (LED) prototype is further fabricated by employing the as-prepared CsPbMnCl QDs as color conversion materials on a commercially available 365 nm GaN LED chip.

Probing molecule-like isolated octahedra via phase stabilization of zero-dimensional cesium lead halide nanocrystals

“…Here, although PL QY of undoped Cs 4 Pb(Br/Cl) 6 nanocrystal is low (5%), the overall QY substantially increased to 32% upon Mn 2+ doping, under 365 nm excitation (Table 2, Supplementary Figure 11a, and Supplementary Note 8). Highest PL QY of 29% was obtained for Cs 4 Pb(Br/Cl) 6 :10% Mn and Cs 4 PbCl 6 :10% Mn (Table 2), which is among the best values reported for Mn 2+ emission (Supplementary Table 8) 46 . In addition, Mn 2+ luminescence was the highest at lower (365 nm) and higher excitation energy (290 nm), for Cs 4 Pb(Br/Cl) 6 and Cs 4 PbCl 6 , respectively, due to their suitable band gaps (determined by halide species), enabling efficient energy transfer to Mn 2+ .…”

Organic–inorganic metal halide hybrids beyond perovskites

“…As a result, a spin-forbidden 4 T 1 -6 A 1 Mn d-electron emission with a long lifetime of a few microsecond was observed and the PLQEs of Mn-doped NCs were dramatically increased. Despite the high Mn substitution ratio of up to 46%, the crystal structure of the host remained mostly unchanged [153]. Besides doped all inorganic perovskite materials, Im et.…”

Lead-free hybrid perovskites for photovoltaics

“…Up to 46% Pb 2+ ions can be exchanged with Mn 2+ in CsPbCl 3 NCs produced by hot-injection, resulting in a highly increased photoluminescence (PL) efficiency [100]. Mixed MAPb x Mn 1− x I 1+2 x Cl 2−2 x ( x = 0.1–1.0) synthesized by a solid-state reaction displayed an unprecedentedly high open-circuit voltage of up to 1.19 V and fill factor (FF) of almost 90% when introduced into inverted solar cells with PEDOT:PSS and PCBM charge transport layers [101].…”