Design strategies of rare-earth luminescent complexes with zero thermal quenching protected by the wire-in-tube structure and the construction of a W-WLED with highly stable illumination and colour reproduction†

Abstract

Efficient and low-cost lighting technologies can alleviate energy and environmental crises and help achieve the goal of “dual carbon”. Traditional cold white light is not suitable for indoor lighting as the blue light emitted damages the human eye, stimulates the nerves, and causes physical and psychological damage. Hence, the TbSSA@ZnO/SnO₂ green phosphor with a wire-in-tube structure was constructed and mixed with commercial blue and red phosphors to assemble a warm white light emitting diode (W-WLED). The shell of ZnO/SnO₂ can effectively protect the homemade terbium complex (TbSSA) core to resist the high operating temperature of 200 °C, and the introduction of Sn⁴⁺ promotes the luminescence intensity. The assembled W-WLED has a related color temperature (CCT) of 2858 K, color purity (R_a) of 89.8, and external quantum efficiency of 12.4%, while stable illumination is retained under the floating driving currents. The prepared W-WLED also has high color reproduction and warm white color temperature, which has important practical significance in the field of semiconductor lighting with complex working environment and high color rendering requirements.