Low-dimensional perovskite nanoplatelet synthesis using in situ photophysical monitoring to establish controlled growth

Abstract

CsPbBr3 nanoplatelets are synthesized with fine control over size, thickness and optical properties. In situ photoluminescence measurements are used to optimize platelet growth.

Revealing the Dynamics of Hybrid Metal Halide Perovskite Formation via Multimodal In Situ Probes

“…In this study, in the Pb–halide routes, Δ E = 140–150 meV, which indicates a significantly larger change from nuclei size to grain size. Although the chemistry used for the synthesis of 3D MAPbI 3 films is different than that for the synthesis of nanocrystals (typically no surface ligands are used for the synthesis of thin films), we propose that nucleation starts on the nanometer scale (or sub‐micrometer scale), similar to the initial stages of nanocrystal growth . In the latter, ligands would terminate the growth of nanocrystals and therefore dominate spectral PL emission (size effect), while in thin films, PL emission is related to the bandgap.…”

Optical Absorption‐Based In Situ Characterization of Halide Perovskites

“…Reproduced with permission. [39] Copyright 2019, Royal Society of Chemistry. e) Evolution of PL peak position and corresponding FWHM during nanocrystal growth.…”

“…by hot injection or halide precursor injection) red shifting of the PL maximum and peak narrowing is observed until PL emission wavelength is constant indicating nucleation and growth until growth is terminated (Figure 3d). [39] [90] It was concluded that the size of the nanocrystals cannot be controlled by the growth time but is controllable with the reaction temperature. [39] [89] In these studies nucleation kinetics were not quantified, nor attempted to interpret via classical nucleation theory but the results demonstrate that in situ PL could be used to extract detailed kinetics with respect to synthesis condition such as temperature or chemical composition.…”

“…[39] [90] It was concluded that the size of the nanocrystals cannot be controlled by the growth time but is controllable with the reaction temperature. [39] [89] In these studies nucleation kinetics were not quantified, nor attempted to interpret via classical nucleation theory but the results demonstrate that in situ PL could be used to extract detailed kinetics with respect to synthesis condition such as temperature or chemical composition. In a separate study in the domain of nanocrystal synthesis, in situ PL has been used successfully for parametric screening of quinary Cs x FA 1−x Pb(Br 1−y I y ) 3 compositions with the goal to optically engineer and fine tune emission between 700-800 nm.…”

“…[85] This example demonstrates how in situ PL can be implemented in high throughput experimentation to enable compositional (PL peak position) and quality control (PL FWHM and PL quantum yield) during synthesis ( Figure 3e) [85][91] as well as for the screening of synthetic conditions such as temperature and ligand ratio. [39] Next, in situ PL measurements can be very powerful in monitoring chemical composition tuning…”