# Controllable Room-Temperature Synthesis of Highly Stable CsPbBr3 Perovskite Quantum Dots via Synergistic Optimization of Br/Pb and OA/OAm Ratios

## TL;DR

This paper presents a method to synthesize stable CsPbBr3 quantum dots at room temperature by optimizing Br/Pb and OA/OAm ratios, leading to improved optical properties and potential for display applications.

## Contribution

A controllable room-temperature synthesis method for highly stable CsPbBr3 quantum dots through synergistic optimization of Br/Pb and OA/OAm ratios.

## Key findings

- Controlling Br/Pb and OA/OAm ratios affects the size, crystalline phase, and surface passivation of CsPbBr3 quantum dots.
- Optimal Br/Pb and OA/OAm ratios (75 and 1.5) result in dense ligand coverage, superior defect passivation, and improved stability.
- LEDs made with these quantum dots achieve a wide color gamut of 129.45% of the NTSC standard.

## Abstract

CsPbBr3 perovskite quantum dots (QDs) have attracted significant attention for optoelectronic applications owing to their outstanding optical properties, yet achieving controlled synthesis with high stability under mild conditions remains a challenge. The room-temperature synthesis of CsPbBr3 perovskite quantum dots using a coprecipitation method is systematically investigated in this work, with an emphasis on how the structural and optical properties of the QDs are influenced by the Br/Pb ratio and OA/OAm ratio. The findings show that controlling the Br/Pb and OA/OAm ratios can effectively influence the size, crystalline phase, and surface passivation properties of CsPbBr3 quantum dots. The photoluminescence peak shifts blue and the bandgap widens when the Br/Pb ratio rises due to a decrease in quantum dot size. This is mainly explained by more effective surface covering by Br− ions and increased quantum confinement effects. The resultant quantum dots demonstrate ideal optical performance at a Br/Pb ratio of 75 and an OA/OAm ratio of 1.5, with dense ligand coverage, superior defect passivation, and markedly improved stability under UV irradiation and in aqueous environments. Variations in the Br/Pb and OA/OAm ratios affect the binding configuration and coverage of ligands on the quantum dot surface, thereby influencing the relationship between non-radiative recombination and the quantum confinement effect. The LED fabricated with the as-synthesized high-performance quantum dots demonstrates a wide color gamut, covering 129.45% of the NTSC standard, indicating strong potential for display applications.