Quantum Dots: Perovskite Quantum Dots with Near Unity Solution and Neat‐Film Photoluminescent Quantum Yield by Novel Spray Synthesis (Adv. Mater. 7/2018)

Spray‐Assisted Coil–Globule Transition for Scalable Preparation of Water‐Resistant CsPbBr3@PMMA Perovskite Nanospheres with Application in Live Cell Imaging

“…Morphology of the CPB PQDs isolated form the PET solution retained their cubic shape according to the TEM image in Figure a, with interplanar distances of 0.58 nm corresponding to (001) crystal facets (insetted in Figure a) identified as cubic phase perovskites . However, as shown in the size distribution pattern in Figure b, the particle sizes after the second precipitation have significantly decreased to between 4 and 10 nm with an approximate average size of 8 nm that can be attributed to further confinement of the PQDs due to the decrease in solvent polarity . This was also supported by the retained PLQYs of 90% for CPB PQDs in PET.…”

Tuning of Amplified Spontaneous Emission Wavelength for Green and Blue Light Emission through the Tunable Composition of CsPb(Br1–xClx)3 Inorganic Perovskite Quantum Dots

“…36 The aggregation of QDs is usually accompanied by serious degradation of the optical properties because of light scattering by QD aggregates (reduction in transmittance in the film) and luminescence quenching by Forster resonance energy transfer. 37,38 The PL quenching of QDs in solution is higher than in the film, which we could attribute to the combination of ligand dissociation and easy surface oxidation upon exposure to a minimal amount of air and degradation over time. 37,38 Moreover, in the solution state, the solvent type is sensitive, for example when a polar solvent was added to the as-synthesized QD suspension, aggregation of QDs may occur because of the hydrophobic nature of the QD surfaces.…”

“…37,38 The PL quenching of QDs in solution is higher than in the film, which we could attribute to the combination of ligand dissociation and easy surface oxidation upon exposure to a minimal amount of air and degradation over time. 37,38 Moreover, in the solution state, the solvent type is sensitive, for example when a polar solvent was added to the as-synthesized QD suspension, aggregation of QDs may occur because of the hydrophobic nature of the QD surfaces. 37,38 To improve the dispersion of QDs, surface ligands on QDs were adjusted by ligands that were more compatible.…”

Metal Halide Perovskite Nanocrystals: Synthesis, Post-Synthesis Modifications, and Their Optical Properties

“…Dai et al mixed both good solvents and poor solvents by means of a spray, producing MAPbBr 3 NCs with a good size distribution. 179 In this particular approach, the precursor’s solution (MABr, PbBr 2 , OA, octylamine in DMF) was sprayed onto a poor solvent (toluene). The micrometer-sized droplets of the sprayed solution are believed to provide a large contact surface area between the two solutions, allowing for a more homogeneous mixing.…”