Ba2YNbO6:Mn4+-based red phosphor for warm white light-emitting diodes (WLEDs): Photoluminescent and thermal characteristics

Abstract

A commercial Mn4+-doped phosphor with deep-red emission has attracted attention in recent years. This can provide red components in the fabrication of warm white light-emitting diodes (WLEDs). The Ba2YNbO6:Mn4+ phosphor is successfully synthesized through conventional solid-state reaction. The crystal structure, composition, and doping site were investigated using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and Raman spectra, respectively. UV–Vis absorption spectra with a broad band ranging from 275 nm to 600 nm demonstrate that it can be efficiently excited by UV/blue light. The photoluminescence spectra exhibit a strong narrow red emission band peaking at 695 nm. The luminescence mechanism has been investigated by Tanabe–Sugano diagram. Nephelauxetic ratio, β1, crystal field strength, Dq, and Racah parameters, B and C, have been evaluated. Thermal characteristics in high and low temperatures have been studied, demonstrating its excellent thermal stability. The values of the activation energy, Ea, have been calculated to explain thermal quenching.