Optical and thermal properties of rare earth–doped K4Ca(PO4)2 phosphor

Abstract

AbstractThe luminescent properties and energy transfer (ET) mechanism in the Ln3+ pair of the RE3+ (RE = Eu3+, Ce3+, Dy3+ and Sm3+) doped K4Ca(PO4)2 phosphor were successfully investigated using a conventional high‐temperature solid‐state reaction. In the near infrared (NIR) range, Ce3+‐doped K4Ca(PO4)2 phosphor exhibited a UV–Vis. emission band, whereas K4Ca(PO4)2:Dy3+ exhibited characteristic emission bands centred at 481 and 576 nm in the near‐ultraviolet excitation range. The possibility of ET from Ce3+ to Dy3+ in K4Ca(PO4)2 phosphor was confirmed by a significant increase in the photoluminescence intensity of the Dy3+ ion based on the spectral overlap of acceptor and donor ions. X‐ray diffraction, Fourier‐transform infrared and thermogravimetric analysis/differential thermal analysis TGA/DTA were carried out to study phase purity, presence of functional groups and amount of weight loss under different temperature regimes. Therefore, the RE3+‐doped K4Ca(PO4)2 phosphor may be a stable phosphor host for light‐emitting diode applications.