Crystal Structures and Luminescence Properties of AIN-deficient Eu2+-activated Ca-alpha-SiAlON Phosphor

Abstract

Eu2+-doped Ca-alpha-SiAlON phosphor was synthesized by normal pressure sintering with conventional tube furnace, and its crystal structures and luminescence properties were investigated. Eu2+-doped Ca-alpha-SiAlON phosphor exhibited an orange light peaking at 583 nm. During the annealing, some of the raw materials evaporated, which resulted in unreacted AlN in the final product. In order to obtain a final product with a single alpha-phase, we prepared samples with various AIN-deficient compositions, and we studied the effects on crystal structures and luminescence properties. For the sample with 15 mol% AlN-deficient composition, 18% enhancement of the intensity was obtained with the disappearance of excess AIN. In addition, the internal quantum efficiency (IQE) was measured using a specially designed integrating sphere, and 56.82% IQE was gained from Eu2+-doped Ca-alpha-SiAlON phosphor.