Single‐Solvent, Ligand‐Free, Gram‐Scale Synthesis of Cs₄PbBr₆ Perovskite Solids with Robust Green Photoluminescence

Abstract

The preparation of luminescent Cs 4 PbBr 6 perovskite solids with current methods either needs a complex procedure, or needs a variety of ligands, and a combination of good solvents and anti-solvents.

A CTAB-mediated antisolvent vapor route to shale-like Cs4PbBr6 microplates showing an eminent photoluminescence

“…[5][6][7][8][9] Up to now, CsPbX 3 (X ¼ Cl, Br, I) perovskite quantum dots (QDs), nanocrystals (NCs), nanowires, and nanoplates as well as Cs 4 PbBr 6 and CsPb 2 Br 5 perovskite-related materials (PRMs) have been routinely synthesized by various solution processing approaches. [10][11][12][13][14][15][16][17] Compared with nanoscale materials, the large-sized perovskites not only possess better stability but also are convenient for application exploration. [18][19][20][21][22][23][24][25][26][27][28] Furthermore, it is well known that the large-sized crystals are very important to identify the essential properties of a material.…”

“…30 More recently, as another number of Cs-Pb-Br family, Cs 4 PbBr 6 PRMs have also attracted enormous attention. [12][13][14][15] It has been revealed that Cs 4 PbBr 6 PRMs have a higher exciton binding energy (E g $ 180 meV) which benets for the recombination of photogenerated charge carriers, resulting in the high efficiency photon emission. 12,33,34 Interestingly, Cs 4 PbBr 6 PRMs endows a very high quantum connement even in the bulk form which make its prospect entirely depends on its crystal structure rather than shape and size.…”

“…12,33,34 Interestingly, Cs 4 PbBr 6 PRMs endows a very high quantum connement even in the bulk form which make its prospect entirely depends on its crystal structure rather than shape and size. 12,15 These merits are critical for the high-performance photoelectric devices such as LEDs. Apart from their excellently emissive properties, Cs 4 PbBr 6 PRMs possess superior high-order nonlinear optical properties in a broad spectral region from 500 to 1500 nm due to the strong connement effects with a high dipole moment.…”

“…Since the pure-phase Cs 4 PbBr 6 perovskite solids with green emission were reported by Bakr et al via a low-temperature solution-processed synthesis, many efforts have been devoted to synthesizing luminescent Cs 4 PbBr 6 perovskite materials. [12][13][14][15] So far, in addition to some micron scale perovskite solid powders with irregular shape, [12][13][14][15] large-sized Cs 4 PbBr 6 single crystals were also successfully prepared by various solution methods. 18,19,31,32 For example, Bastiani et al harvested 500 mm pure-phase Cs 4 PbBr 6 single crystals with smooth surfaces and well-dened rhomboid shape through an antisolvent crystallization process.…”

“…18 As is known, unlike CsPbBr 3 possessing a higher symmetry simple cubic structure with connected corner-sharing PbBr 6 4À octahedra, the PbBr 6 4À octahedra in Cs 4 PbBr 6 are fully isolated from each other in the crystal lattice with interspersed Cs + cations. 12,13,15,33,34 Therefore, the large-sized Cs 4 PbBr 6 PRMs reported generally have an irregular or rhomboid shape but the plate-like Cs 4 PbBr 6 perovskite crystals are rarely reported until now. [12][13][14][15]18,19,31,32 Therefore, developing an effective route for the synthesis of large scale plate-like Cs 4 PbBr 6 perovskite materials with highly photoluminescence is of great signicance for practical applications.…”