Creating chromaticity palettes and identifying white light emitters through nanocrystal megalibraries.

Cai, Tong; Shin, Donghoon; Li, Jun; Xu, David D; Pietryga, Jacob; Zhang, Ye; Mirkin, Chad A · Sci Adv · 2025

basic_science · Level V

Where this comes from

Abstract

Halide perovskites are used to fabricate energy-efficient optoelectronic devices. Determining which compositions yield desired chromatic responses is challenging, especially when doping strategies are used. Here, we report a way of mapping the compositional space of halide perovskites to generate a light emission or "chromaticity" palette. Megalibraries consisting of millions of Mn<sup>2+</sup>-doped PEA<sub>2</sub>PbX<sub>4</sub> (PEA: phenethylammonium, X: halide anions) perovskite nanocrystals were synthesized to screen the compositions that led to specific emission profiles. The chromaticity palette allows one to identify single-composition white light emitters [PEA<sub>2</sub>Pb<sub>1-<i>y</i></sub>Mn<i><sub>y</sub></i>(Br<sub>1-<i>x</i></sub>I<i><sub>x</sub></i>)<sub>4</sub> (0 ≤ <i>x</i> ≤ 1, 0 ≤ <i>y</i> ≤ 1)], eliminating the need for trilayer structures in conventional white light-emitting diodes, which are prone to instability and complex device designs. Optical studies reveal that the dual-wavelength photoluminescence emission originates from exciton recombination and energy transfer processes. This study shows how emerging megalibrary capabilities can rapidly advance our understanding of the complex composition-structure-function relationships and be used to accelerate the discovery of next-generation optoelectronic materials.