White light emission from a ternary dysprosium complex: Energy transfer and ligand-driven modulation

Abstract

This study explores the preparation and spectral properties of four luminescent dysprosium (III) complexes: [Dy (TTBD)₃L], where L represents different auxiliary ligands, including Phen (D1), Neo (D2), BP (D3) and BC (D4). The successful synthesis of these complexes was confirmed through a combination of CHN analysis, IR spectroscopy and Proton NMR spectroscopy. Optical properties were systematically assessed by UV–visible absorption spectroscopy, photoluminescence (PL) spectroscopy and radiative decay lifetime measurements. CIE coordinates, plotted in the 1931 color space, were used to identify the emissive color of the complexes. Complex D2 emitted white light, D3 showed bluish-white emission, while D1 and D4 exhibited blue luminescence due to a broad, ligand-based emission band. In addition, the thermal stability and electrochemical behavior of the complexes were assessed. This thorough analysis seeks to elucidate the structure-optical properties relationship, focusing on emission modulation for potential applications in white OLEDs and other optoelectronic devices. The study emphasizes the importance of controlling energy transfer interactions between donor and acceptor moieties to tune the emission spectra. We demonstrate that by carefully selecting different sensitizers for the Dy(III) ion, a range of color outputs, including pure white light from a single-phase material, can be achieved, offering promising pathway for advanced display and lighting technologies.