Circularly Polarized Near-Infrared Electroluminescence from Chromium(III) Complex-Based OLEDs

Small. 2026 Jan;22(1):e12638. doi: 10.1002/smll.202512638. Epub 2025 Nov 18.

Abstract

Organic light-emitting diodes (OLEDs) featuring circularly polarized (CP) electroluminescence (EL) are gaining tremendous attention for their potential in advanced display and photonic applications. Chiral organic molecules and 4d and 5d metal complexes have been extensively studied for their role in the emissive layer of these devices. Here, pioneering work demonstrating EL emission from a chromium(III) complex is presented. Notably, by leveraging the highly polarized spin-flip transitions of enantiopure CrIII complexes, a proof-of-concept device showcasing near-infrared (NIR) CP EL with peaks at 726 and 747 nm and corresponding dissymmetry values up to 0.015 and -0.029 is developed. These findings highlight the potential of earth-abundant CrIII complexes for cutting-edge chiral optoelectronic applications in medicine, security, and quantum communications.

Keywords: CPL; CP‐NIR‐OLEDs; chromium; electroluminescence; spin‐flip.