# Ligand-Mediated, Temperature-Tuned Synthesis of CsPbBr3 Nanosheets for Ordered Superlattice Assembly

## TL;DR

Scientists developed a new method to create perovskite nanosheets with precise control over their size and structure, leading to better performance in optoelectronic devices.

## Contribution

A modified ligand-assisted hot-injection strategy enables controlled synthesis of CsPbBr3 nanosheets with tunable optical properties and ordered superlattice assembly.

## Key findings

- Nanosheets with thicknesses of 3.35 ± 0.05 nm and 4.05 ± 0.09 nm were produced at 130 and 140 °C, respectively.
- Superlattices showed tunable photoluminescence peaks at 462, 464, and 513 nm with decay times ranging from 8.65 to 35.49 ns.
- Ordered superlattices preserved intrinsic emission properties, indicating structural stability and scalability.

## Abstract

Two-dimensional (2D) colloidal CsPbBr3 nanosheets (NSs) possess size-dependent optoelectronic properties; however, conventional hot-injection methods often lack precise growth control and well-ordered superlattice self-assembly. Herein, we introduce a modified ligand-assisted hot-injection strategy that promotes direct precursor–ligand interactions prior to solvent mixing, thereby enabling highly controlled nanosheet superlattice growth. By adjusting the reaction temperature from 130 to 150 °C, we obtained rectangular nanosheets with monodisperse, well-defined thicknesses of 3.35 ± 0.05 nm and 4.05 ± 0.09 nm at 130 and 140 °C, respectively, both below the 7 nm exciton Bohr diameter, consistent with strong quantum confinement. The resulting superlattices exhibited sharp, tunable photoluminescence peaks at 462, 464, and 513 nm, with time-resolved PL revealing a clear size–lifetime correlation, where smaller lateral superlattices at 130 °C showed a short decay time of 8.65 ns, intermediate growth at 140 °C yielded 15.42 ns, and larger lateral superlattices at 150 °C reached 35.49 ns. Importantly, the modified synthesis facilitated the formation of ordered superlattices that preserved their intrinsic emission properties, underscoring their structural stability and scalability. These findings establish a direct link between ligand-mediated synthesis, reaction temperature, nanosheet dimensions, and optical performance, offering a pathway to high-quality perovskite NS superlattices for advanced optoelectronic applications such as light-emitting diodes and sensors.