Photoluminescence properties of LiY(WO₄)₂:Bi 3+ , Eu 3+ phosphors for white light-emitting diode applications

Pristine LiY(WO₄)₂ and Bi3+, Eu3+ singly and co-doped LiY(WO₄)₂ tungstate phosphors were synthesised using the solid-state reaction (SSR) method. Powder X-ray diffraction (PXRD) analysis confirmed the formation of a wolframite-related structure with a P2/n space group. Under ultraviolet (UV) excitation, the phosphors exhibited distinct emission colours due to efficient energy transfer (ET) from the [WO₄]2− group to the Bi3+ and Eu3+ ions. The photoluminescence (PL) spectra showed greenish-yellow emission from Bi3+ at 513 nm under 336 nm excitation and red emission from Eu3+ at 615 nm under 300 nm excitation. The CIE colour coordinates, derived from the PL emission data, indicated that LiY(WO₄)₂:Bi3+, Eu3+ is an efficient phosphor suitable for applications such as white light-emitting diodes (wLEDs) and display devices.