# Inorganic–Organic Multicoating Layer Encapsulation of Formamidine Lead Halide Perovskite Quantum Dots for Lighting Applications

## TL;DR

This paper introduces a new method to stabilize green perovskite quantum dots using a dual-layer coating, making them more durable for lighting and display applications.

## Contribution

A cost-effective dual-layer encapsulation strategy using SiOx and 513M is proposed to enhance the environmental stability of FAPbBr3 PQDs.

## Key findings

- The multicoated FAPbBr3 PQDs show improved resistance to environmental factors without compromising optical properties.
- The composite material emits at ∼532 nm with a full width at half-maximum of ≤28 nm and a photoluminescence quantum yield of >50%.

## Abstract

Pure-green formamidinium lead bromide (FAPbBr3) perovskite
quantum dots (PQDs) are particularly attractive for display and lighting
applications. However, their inherent instability and processing challenges
hinder their widespread application and commercialization. The instability
of PQDs under exposure to light, heat, water, and oxygen is primarily
attributed to their low formation energy, leading to phase transformations,
agglomeration, and degradation, which negatively impact their optical
properties. To address these challenges, this study proposes a dual-interface
encapsulation strategy that integrates inorganic–organic synergy
and covalent surface coupling into a single hierarchical framework.
In this work, we present a cost-effective hierarchical multicoating
strategy for stabilizing pure-green FAPbBr3 PQDs using
industrially accessible stabilization agents, namely SiO
x
and dicyclopentanyl methacrylate (513M). Specifically,
this research utilizes (3-aminopropyl) triethoxysilane (APTES) as
a coupling agent ligand and tetraethoxysilane to uniformly coat the
PQDs by SiO
x
. Following this, 513M, a
monomer, is radically polymerized on the surface of the SiO
x
-coated PQDs to form a secondary shell layer. The
initial coating enhances the PQDs’ resistance to environmental
factors, while the secondary layer (a hydrophobic polymer) further
improves environmental stability without compromising the PQDs'
structure
during polymerization. The resulting FAPbBr3@SiO
x
@513M composite material, resulted in powder form,
significantly improves the PQDs’ durability against environmental
conditions while maintaining excellent optical properties, including
emission at ∼532 nm, a full width at half-maximum of ≤28
nm, and a photoluminescence quantum yield of >50%, demonstrating
that
robust environmental protection can be achieved without relying on
record-high optical parameters or costly materials. Owing to its use
of low-cost, scalable materials and pure-green emissive PQDs, this
multicoating strategy offers a realistic pathway toward industrially
viable, solid-state PQD materials for optoelectronic applications.