Luminescent properties of SrZn2(PO4)2:Tb3+ and its luminescence improvement by incorporating A+ (A=Li, Na, and K)

Abstract

A novel green phosphor SrZn2(PO4)2:Tb3+ is synthesized by a high temperature solid-state method, and its luminescent property is investigated. X-ray diffraction patterns of SrZn2(PO4)2:Tb3+ indicate a similarity crystalline phase to SrZn2(PO4)2. SrZn2(PO4)2:Tb3+ shows green emission under 369nm excitation, and the prominent luminescence in green (544nm) due to 5D4–7F5 transition of Tb3+. For the 544nm emission, excitation spectrum has several excitation band from 200nm to 400nm. Emission intensity of SrZn2(PO4)2:Tb3+ is influenced by Tb3+ concentration, and concentration quenching effect of Tb3+ in SrZn2(PO4)2 is also observed. With incorporating A+ (A=Li, Na, and K) as compensator charge, the emission intensity of SrZn2(PO4)2:Tb3+ can be obviously enhanced. CIE color coordinates of SrZn2(PO4)2:Tb3+ locate in the green region. The results indicate this phosphor may be a potential application in white LEDs.