New Multicolor Tungstate-Molybdate Microphosphors as an Alternative to LED Components

Due to the ongoing need to create phosphors with the appropriate emission color for the production of light emitting diodes, we decided to synthesize a series of multicolour microphosphors with tunable visible emissions, depending on the composition of dopant ions. In this work, we investigated the structure, morphology, and luminescent properties of new molybdate-tungstate phosphors co-doped with Tb³⁺ and Eu³⁺ ions. The conventional high temperature solid state method was used to prepare a series of CaMo_yW_1-yO₄:Eu³⁺_x/Tb³⁺_1-x materials. In order to obtain phosphors with the most promising luminescent properties, the experiment was planned by taking into account the different composition of the matrix and the concentration of the particular dopant ions (Eu³⁺_x/Tb³⁺_1-x, x = 0.001, 0.003, 0.005, 0.007, 0.009). As a result, luminescent materials were obtained with a pure tetragonal crystal structure, the space group of I4₁/a, confirmed by X-ray diffraction (XRD). The size and shape of the particles obtained from the materials were analyzed based on scanning electron microscopy images. Luminescence spectroscopy (excitation and emission spectra, decay lifetimes) was utilized to characterize the luminescence properties of the as-prepared phosphors. The color change of the emission from green-yellow to orange-red was confirmed using the 1931 Comission Internationale de l'Eclairage (CIE) chromaticity coordinates and color correlated temperature (CCT).