Near-Unity Red Mn²⁺ Photoluminescence Quantum Yield of Doped CsPbCl₃ Nanocrystals with Cd Incorporation

Abstract

Although Mn 2+ doping in semiconductor nanocrystals (NCs) has been studied for nearly three decades, the near 100% photoluminescence (PL) quantum yield (QY) of Mn 2+ emission has never been realized so far. Herein, greatly improved PL QYs of Mn 2+ emissions are reported in Mn 2+doped CsPbCl 3 NCs with various Mn 2+ doping concentrations after CdCl 2 post-treatment at room temperature. Specifically, the near-unity QY and near single-exponential decay of red Mn 2+ emission peaking at 627 nm in doped CsPbCl 3 NCs are obtained for the first time. The temperature dependence of steady-state and time-resolved PL spectra reveals that the CdCl 2 posttreatment significantly reduces the nonradiative defect states and enhances the energy transfer from host to Mn 2+ ions. Moreover, the Mn 2+ :CsPbCl 3 NCs after CdCl 2 post-treatment exhibit robust stability and high PL QYs after multipurification. The results will provide an effective route to obtain doped perovskite NCs with high performance for white lighting emitting diodes.

Lead‐Free Halide Double Perovskites: Structure, Luminescence, and Applications

“…However, considering the success of doped emission in OIHPs and the research on HDPs is at the very beginning, the future for the next decade of RE doping in HDPs is worth expecting. [ 194 ]…”

Ultrathin Monolayer Mn2+‐Alloyed 2D Perovskite Colloidal Quantum Wells

“…[ 9,10 ] Similar to other semiconductor materials, doping mechanism were also chosen extensively to modify the functional properties expanding. [ 11–19 ] Among these, manganese (Mn 2+ ) doped CsPbX 3 NCs were being actively pursued due to the interesting optical, electronic and magneto‐optic properties introduction, which have been well‐known in II–VI chalcogenide semiconductor doping NCs. [ 20–26 ] Exciton energy transfer achieved in Mn 2+ dopant perovskite CsPb(Cl/Br) 3 NCs, realizing new identify high‐efficient luminescence originates from the Mn 2+ spin‐forbidden electronic 4 T 1 to 6 A 1 transition in millisecond time scale lifetime.…”

Surface Passivation Strategies for Improving Photoluminescence and Stability of Cesium Lead Halide Perovskite Nanocrystals

“…[34] The partial replacement of Pb 2 + cation with manganese or lanthanide ions gives rise to multi-colour emission in visible and NIR regions in CsPbCl 3 perovskite NCs. [35][36][37] Doping with metal ions like Cd 2 + , Ni 2 + which are smaller in size than Pb 2 + ion gives an enhancement of 20 folds in PLQY of CsPbCl 3 perovskite NCs. [38,39] To target the extrinsic stability of CsPbX 3 NCs towards heat, moisture, and oxygen, it is necessary to look for the approaches such as encapsulation in a polymer matrix, and developing core-shell structures.…”

“…[43] Additionally, it has been proved that doping of sodium to protect CsPb(Br/I) 3 perovskite NCs during encapsulation with Al 2 O 3 to form Na: CsPb(Br/I) 3 @Al 2 O 3 nanocomposites makes them less vulnerable to moisture and light exposure. [44] So far, many approaches have been developed to attain high stability and photoluminescence of CsPbX 3 perovskite NCs like surface passivation, [45][46][47][48] metal doping, [35,36,38,49] modified synthesis procedures, [17,18,50,51] core-shell, [43,44,52] encapsulation, [42,53,54] etc (See Figure 2). These methods are very diverse and their outcomes are much varied.…”

“…For example, the exchange of Cs + ion with FA + ions using FA‐oleate precursor in CsPbI 3 perovskite NCs can increase the stability and NIR emission of perovskite NCs [34] . The partial replacement of Pb 2+ cation with manganese or lanthanide ions gives rise to multi‐colour emission in visible and NIR regions in CsPbCl 3 perovskite NCs [35–37] . Doping with metal ions like Cd 2+ , Ni 2+ which are smaller in size than Pb 2+ ion gives an enhancement of 20 folds in PLQY of CsPbCl 3 perovskite NCs [38,39] …”