Evolution and Mechanism of Cesium Lead Bromide Nanostructures in Oleylamine‐Rich System by Hot‐Injection Method

Abstract

as high photoluminescence quantum yield (PLQY), [6] high carrier mobility, [7] adjustable band gap, [1,8] facile and diverse synthesis methods. [1,[9][10][11] CsPbBr 3 have potential applications in solar cells, [12] light-emitting diodes (LEDs), [13] lasers, [11] photodetectors, [14] and other optical devices. [15][16][17] CsPbBr 3 nanowires are 1D nanostructures with long carrier diffusion lengths, showing outstanding applications in optical fields. [18,19] The hot-injection method is an effective method for synthesizing CsPbBr 3 nanostructures. [1,2] Figure 1 shows the crystal structure models of the possible compounds during the synthesis process. Pb 2+ ions have a strong coordination ability with halide ions (e.g., Br − ) in octadecene solution, existing in the form of [PbBr 6 ] 4− octahedrons. [20,21] The Cs + ions separate the [PbBr 6 ] 4− octahedrons, forming Cs 4 PbBr 6 structure (Figure 1a). [22,23] As a

Influence of Binary Ligands in Designing Cesium Lead Halide (CsPbX3, X = Cl, Br, I) Perovskite Nanocrystals-Oleic Acid and Oleylamine

“…During synthesis, the self-assembled one-dimensional CsPbBr 3 NWs can be achieved by forming lamellar structures [70,96]. Moreover, the OAm-rich synthesis reaction at 180 • C could direct the formation of self-assembled CsPbBr 3 NWs [97]. In this case, the self-assembly of NWs takes place by connecting [PbBr 6 ] 4− octahedrons under a longer reaction period.…”

“…Other possibilities, such as ligand environment and soft ligand templating, are also proposed as reasons for this phase transformation. Li et al observed that when the synthesis reaction is carried out in an OAm-rich atmosphere, temperature and reaction time significantly influence the formation of perovskite NCs [97]. In this case, the authors achieved Cs 4 PbBr 6 NCs at 160 • C and CsPbBr 3 NCs at 180 • C. It was found that in contrast with CsPbBr 3 NCs, where the substitution of Cs + takes place by OAm + cations, Cs 4 PbBr 6 is comprised of both OAm and OA in a bonded state as an OAm + -OA − complex [49].…”

“…Other possibilities, such as ligand environment and soft ligand templating, are also proposed as reasons for this phase transformation. Li et al observed that when the synthesis reaction is carried out in an OAm-rich atmosphere, temperature and reaction time significantly influence the formation of perovskite NCs [97]. In this case, the authors achieved Cs4PbBr6 NCs at 160 °C and CsPbBr3 NCs at 180 °C.…”

Suppressing Growth Strategy on Synthesizing Stable and High-Quality Blue-Emitting CsPbBr3 Quantum Dots

“…Previously, we reported a hot-injection process for CsPbBr 3 nanowires with various sizes in the OAm-rich system without ODE as the solvent and found that OAm and OA showed different reactivity to Cs + , Pb 2+ , and Br − ions. 36,37 This work further changes the ratio of OA to OAm during the hotinjection process without OED, hereafter called as the modified hot-injection method (MM), to slow the growth process and obtain ultra-small, high-quality perovskite QDs. The results prove that the growth process of CsPbBr 3 can be effectively suppressed, and ultra-small CsPbBr 3 QDs with strong confinement and fewer defects are obtained.…”