Photoluminescence properties of β-SiAlON:Yb2+ a novel green-emitting phosphor for white light-emitting diodes

摘要

We have synthesized Yb²⁺-activated Si6−zAlzOzN8−z (0.05⩽z⩽2.3, 0.03 mol% ⩽Yb²⁺⩽0.7 mol%) green phosphors by solid-state reaction at 1900 °C for 2 h under a nitrogen pressure of 1.0 MPa. Phase purity, photoluminescence and its thermal quenching were investigated. A single phase was obtained for all values of z and Yb²⁺ concentration. A distinct emission band was observed at 540 nm originating from the 5d–4f electronic transition in Yb²⁺ under 480 nm excitation. The photoluminescence properties mainly depended on the Yb²⁺ concentration and chemical composition of the matrix. The resultant phosphor showed high thermal stability, that is, the emission intensity at 150 °C was about 82% of that measured at room temperature. The experimental results indicate that β-SiAlON:Yb²⁺ is a potential green phosphor for white light-emitting diodes (LEDs), which use blue LEDs as the primary light source.