Green Emission from Calcium Zirconium Silicate Doped with Trivalent Terbium Phosphor

Trivalent terbium ion (Tb 3+ )-doped calcium zirconium silicate (Ca 3 ZrSi 2 O 9 ) phosphors (Ca 3 ZrSi 2 O 9 : x Tb 3+ ), with molar composition 0.005 ≤ x ≤ 0.13, were effectively produced by the standard sol–gel method. The synthesized samples were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform-infrared (FT-IR) spectroscopy, photoluminescence (PL) excitation and PL emission. XRD spectral profiles of the prepared samples demonstrate the formation of a monoclinic structure. SEM micrographs of the Ca 3 ZrSi 2 O 9 : x Tb 3+ phosphor samples show chunky solids interlocked in a tile-like pattern. The FT-IR spectra reveal the structure and bond activities of the samples. The PL excitation spectra demonstrate the 4 f 8 → 4 f 7 5 d 1 transitions of Tb 3+ ions under 545 nm emission wavelength. The PL emission spectra of Tb 3+ ions recorded under 243-nm excitation wavelength exhibit 5 D 3 → 7 F J ( J = 6, 5, 4) and 5 D 4 → 7 F J ( J = 6, 5, 4, 3) transitions over the wavelength range of 350–650 nm. Of all these emission transitions, the one pertaining to the 5 D 4 → 7 F 5 transition around 545 nm is strong and attributed to green emission. The photometric analysis also confirms the green emission from the Ca 3 ZrSi 2 O 9 :0.09Tb 3+ phosphor, which further supports its potential application in the fabrication of LEDs and in solid state display applications.