In Situ Ambient Preparation of Perovskite-Poly-L-Lactide acid phosphors for Highly Stable and Efficient Hybrid Light Emitting Diodes

TL;DR

This paper presents a novel in-situ ambient synthesis method for stable, high-efficiency perovskite-polymer phosphors used in durable, high-performance hybrid LEDs, advancing sustainable lighting technology.

Contribution

It introduces the first ambient in-situ fabrication of MHP-bio-polymer phosphors with high stability and efficiency, using a low-cost, one-pot process at room temperature.

Findings

Achieved high photoluminescence quantum yields (>85%)

Demonstrated operational stability of ca. 600 hours in LEDs

Produced LEDs with luminous efficiencies up to 73 lm W-1

Abstract

Metal halide perovskites (MHPs) based phosphor-converted light-emitting diodes (pc-LEDs) are limited by the low MHP stability under storage/operation conditions. A few works have recently stablished the in-situ synthesis of MHPs into polymer matrices as an effective strategy to enhance MHPs stability with a low-cost fabrication. However, this is limited within petrochemical-based polymers. Herein, the first in-situ ambient preparation of highly luminescent and stable MHPs-bio-polymer filters (MAPbBr3 nanocrystals as emitter and poly(L-lactide acid) (PLLA) as matrix) with arbitrary areas (up to ca. 300 cm2) is reported. The MAPbBr3-PLLA phosphors feature a narrow emission (25 nm) with excellent photoluminescence quantum yields (more than 85%) and stabilities under ambient storage, water, and thermal stress. This is corroborated in green pc-LEDs featuring a low efficiency roll-off, excellent operational stability of ca. 600 h, and high luminous efficiencies of 65 lm W-1 that stand out the prior art (e.g., average lifetime of 200 h at 50 lm W-1). The filters are further exploited to fabricate white-emitting pc-LEDs with efficiencies of ca. 73 lm W-1 and x/y CIE color coordinates values of 0.33/0.32. Overall, this work stablishes a straightforward (one-pot/in-situ) and low-cost preparation (ambient/room temperature) of highly efficient and stable MHP-bio-polymer phosphors for highly performing and more sustainable lighting devices.