Organic Sulfonium‐Stabilized High‐Efficiency Cesium or Methylammonium Lead Bromide Perovskite Nanocrystals

Abstract

Herein, we report a new X-type ligand, i.e., organic sulfonium bromide, for high-efficiency CsPbBr 3 and MAPbBr 3 (MA = methylammonium) perovskite nanocrystals (PNCs). We first confirmed the facile synthesis of the titled ligands in N,N-dimethylformamide at room temperature. By reacting dodecylmethylsulfide with allyl bromide, (3-bromopropyl)trimethoxysilane, and 1,4-dibromobutane, respectively, three representative ligands (named DAM, DSM, and DMM) are acquired. All of them result in CsPbBr 3 and MAPbBr 3 PNCs with near-unity photoluminescence quantum yield (PLQY) and decent ambient stability (no less than 90 % PLQY after 2 months) using a room-temperature ligand-assisted reprecipitation technique. Among them, DSM and DMM endow CsPbBr 3 PNCs with higher thermal/light stability arising from the cross-linkable or bidentate ligand structure. Further, DSM-CsPbBr 3 PNCs can be incorporated into polystyrene through in situ thermal polymerization and the composite shows a record-high PLQY of 93.8 %.

Inorganic Ligand Triggered Transformation from Cs4PbBr6 Nanocrystals to Blue-Emitting CsPbBr3 Nanoplatelets

“…33 In a polar environment, a noticeable red-shift around 15 nm in the PL emission was observed after 1 day, since ligands binding to the nanocrystal surface are highly dynamic, leading to the optical performance of NPLs vulnerable to external stimuli (isopropanol) from the storage conditions, in which surface defects are readily formed since the protective outer ligands gradually fall off (Figure S17a). 44 Instead, the blue-emitting CsPbBr 3 NPLs in the nonpolar system always maintain good monochromaticity, and their luminescence position has no obvious fluctuation (Figure S17b). It is worth mentioning that a small difference in the polarity of the solvent needs to be considered during the synthesis and purification to ensure the crystal quality.…”

Self-Trapped Exciton Emission in Highly Polar 0D Hybrid Ammonium/Hydronium-Based Perovskites Triggered by Antimony Doping

“…To date, a wide variety of monovalent cations, including alkali inorganic cations (Cs, Rb, and K), as well as various organic cations formed by protonation, have been extensively utilized to form perovskite structures with different characteristics. ,,,− For example, N + -based onium cations such as protonated ammonia, R-NH 3 + have garnered attention . Additionally, P + - and S + -based onium cation (phosphonium and sulfonium) hybrid perovskites have also attracted great interest in recent studies. − Although these cations offer advantageous passivation and improved chemical stability owing to their hydrophobic character, they are typically non- or weakly polar, which results in minimal influence on STE emissions. , Hydronium cations are a promising option as the polar A-site cation owing to the strong electronegativity of oxygen and the presence of remaining lone-pair electrons, yet their use in perovskite structures remains uncommon. , Among the various hydronium ions, the protonated water molecule OH 3 + stands out as the simplest and most stable form. In this study, we incorporated ammonium cation NH 4 + and hydronium cation OH 3 + with [InCl 6 ] 3– to form a novel hybrid 0D polarized perovskite host.…”

Ligand Strategy for Perovskite Displays: A Review

“…Ensuring structurally stable, uniform, and efficient perovskite quantum dot color conversion layers/films (PQDCCLs/PQDCCFs) is the key to active-matrix PL devices. 79 Luckily, Xie's group 80 developed a ligand strategy to form stable PQDCCFs. They first dissolved dodecyl methyl sulfide and three different short-chain structured ligand functional groups individually in DMF, thus obtaining three new longchain ligands (Figure 4(b)).…”

“…(b) Performance enhanced by long-chain ligand interactions. Reproduced with permission from ref . Copyright 2022 Wiley Online Library.…”

“…Luckily, Xie’s group developed a ligand strategy to form stable PQDCCFs. They first dissolved dodecyl methyl sulfide and three different short-chain structured ligand functional groups individually in DMF, thus obtaining three new long-chain ligands (Figure (b)).…”