Structural and photoluminescence properties of europium (III)-activated lithium meta-silicate phosphors for solid-state lighting

In the present work, a series of Li 2 SiO 3 phosphors activated with the different concentrations of x Eu 3+ ions have been synthesized by solid-state reaction method. First, the concentration of Eu 3+ ions and firing temperature was optimized. The orthorhombic crystal structure of the prepared compound was confirmed by the powder X-ray diffractometry (PXRD) technique. Under the excitation of 394 nm, the emission spectra of xEu 3+ ions show the characteristic emission peaks assigned to transitions of the 5 D 0 → 7 F j ( J = 0, 1, 2, 3, 4), which emits an intense orange–red light peaked at 617 nm. Concentration quenching occurs when the Eu 3+ concentration is beyond 0.04 mol. The Eu 3+ concentration quenching mechanism was verified to be multipole–multipole interaction and the critical transfer distance ( R C ) is calculated to be about 14.13 Å. Commission International Eclairage (CIE), color rendering index (CRI), color correlated temperature (CCT), color purity (CP), and quantum efficiency (QE) have been calculated for each sample and were found well within the defined acceptable range. This result indicates that prepared phosphors emitted in the orange–red region that may be useful in various solid-state lighting.