Optical Properties of Eu²⁺ in α-SiAlON

Abstract

New interesting α-SiAlON:Eu-based yellow oxynitride phosphors with the formula (CaxEuy)Si12-2x-3yAl2x+3yOyN16-y (x = 0.2−2.2, y = 0−0.25) have been prepared, and the effects of the activator concentration and the overall composition of the host lattice on optical properties have been investigated. It has been demonstrated that the Eu2+-doped α-SiAlON phosphors absorb strongly in the UV−visible part of the electromagnetic spectrum and exhibit an intense emission band with peaks at 583−605 nm. We have shown that the optical properties depend greatly on the Eu2+ concentration and the overall composition of the host lattice. The results indicate a concentration quenching effect at y ≥ 0.075 and a systematic red-shift in emission wavelength as the Ca2+ or the Eu2+ concentration increases.