Surface Reconstruction of CsPbBr₃ Nanocrystals by the Ligand Engineering Approach for Achieving High Quantum Yield and Improved Stability

Abstract

Oleylamine/oleic acid (OAm/OA) as the commonly used ligand is indispensable in the synthesis of perovskite nanocrystals (PNCs). Unfortunately, poor colloidal stability and unsatisfactory photoluminescence quantum yield (PLQY) are observed, resulting from a highly dynamic binding nature between ligands. Herein, we adopt a facile hybrid ligand (DDAB/ZnBr 2 ) passivation strategy to reconstruct the surface chemistry of CsPbBr 3 NCs. The hybrid ligand can detach the native surface ligand, in which the acid−base reactions between ligands are suppressed effectively. Also, they can substitute the loose capping ligand, anchor to the surface firmly, and supply sufficient halogens to passivate the surface trap, realizing an exceptional PLQY of 95% and an enhanced tolerance toward ambient storage, UV irradiation, anti-solvents, and thermal treatment. Besides, the as-fabricated white light-emitting diode (WLED) utilizing the PNCs as the green-emitting phosphor has a luminous efficiency around 73 lm/W; the color gamut covers 125% of the NTSC standard.

Effects of Pressure on Exciton Absorption and Emission in Strongly Quantum-Confined CsPbBr3 Quantum Dots and Nanoplatelets

“…Modifying the surface-bound ligand or substitutionally doping the cation sites of the lattice in ways that have been shown to increase the structural stability of MHP NCs will be possible strategies to alter the behavior of the PL at low pressures in future studies. 31,32 ■ CONCLUSIONS We investigated the effects of the pressure on the exciton transitions in strongly quantum-confined CsPbBr 3 QDs and NPLs, each representing two common morphologies of semiconductor NCs with a confined exciton in 0D and 2D structures. Taking advantage of the well-isolated exciton peak from the continuum interband absorption, we revealed the pressure-induced switching off and on of the exciton transition previously not resolvable in nonconfined NCs and the high susceptibility of CsPbBr 3 NPLs to pressure-induced trap creation.…”

“…This has an important implication when using these MHP NPLs for light-emitting applications on a platform that can potentially impose comparable pressures on the NPLs to produce trap states. Modifying the surface-bound ligand or substitutionally doping the cation sites of the lattice in ways that have been shown to increase the structural stability of MHP NCs will be possible strategies to alter the behavior of the PL at low pressures in future studies. , …”

“…Modifying the surface-bound ligand or substitutionally doping the cation sites of the lattice in ways that have been shown to increase the structural stability of MHP NCs will be possible strategies to alter the behavior of the PL at low pressures in future studies. 31 , 32 …”

Synthesis and optical wireless communication application of high efficiency extreme blue CsPbBr3 nanoplates

“…This means randomly distributed Zn 2+ is possibly coordinated by the OA ligand to some extent, which can also play a role in surface passivation. 37,43 The atomic percent of CsPbBr 3 NPls was also quantified semiquantitatively from EDS (Fig. S1, ESI†).…”

FAPbBr3@PbBr(OH) phosphor with high stability for anti-counterfeiting application via water induction

“…Liu et al [23] utilized a fluoride-based post-treatment approach that effectively mitigates the emission thermal quenching of CsPbBr 3 perovskite quantum dots, enhancing their structural thermal stability. Zhang et al [24] used ZnBr 2 /didodecyldimethylammonium bromide hybrid ligands to regulate the desorption of carboxylate/ alkylammonium from the surface of CsPbBr 3 perovskite nanocrystals, breaking with the conventional ligand strategy. This method effectively inhibits acid-base reactions, resulting in stable ligand substitution and halogen compensation.…”