Luminescent performances of Ba9-Ca Al2Si6O24:Eu2+, Mn2+ orthosilicate phosphors along with Ca2+ contents

Abstract

Optical materials composed of (Ba8.8-p-qCap)Eu0.2MnqAl2Si6O24 (p = 2–4, q = 0–0.2) were prepared via a solid-state reaction at high temperature. The X-ray diffraction patterns of the obtained phosphors were analyzed to index the peak positions. The single-phase phosphors showed a trigonal orthosilicate structure with R3‾H symmetry. The photoluminescence emission spectra of the (Ba8.8-pCap)Eu0.2Al2Si6O24 phosphors depending on the Ca2+ ion content (p) were exploited under 365-nm excitation. When the Mn2+ emitter was co-doped in the (Ba8.8-pCap)Eu0.2Al2Si6O24 structure, the energy-transfer mechanism from Eu2+ to Mn2+ was investigated, and their electric multipole interactions were examined. The Commission Internationale de I'Eclairage (CIE) coordinates near the blue-green to orange regions of the obtained phosphors were observed. Thermal quenching with the activation energy of (Ba8.7-pCap)Eu0.2Mn0.1Al2Si6O24 (p = 2–4) phosphors in the temperature range of 298–448 K was achieved under a 365-nm light-emitting diode (LED). The tendency of the internal quantum efficiency of the (Ba5.8-qCa3)Eu0.2MnqAl2Si6O24 (q = 0.01, 0.1, 0.2) phosphors on a 365-nm LED chip was measured in addition to the color-rendering index, correlated color temperature, and CIE coordinates for the white LEDs.