Red-green-blue-tunable emission from Eu3+ and Tb3+ codoped pyrophosphate phosphors

Highlights: • Red-yellow-green-blue color-tunable emission was achieved in MgIn₂P₄O₁₄: EuTb. • Cross-relaxation leads to a color tunable Tb³⁺ emission. • Energy transfer and absorption competition occur between Eu and Tb in MgIn₂P₄O₁₄. -- Abstract: Color-tunable phosphors based on a single host are superior to traditional mixed primary-color phosphors in fluorescent lamps, due to the better consistency of different color components in service. In this work, a series of Eu³⁺/Tb³⁺ doped MgIn₂P₄O₁₄ phosphors were synthesized by a conventional solid state reaction method. The phosphors exhibit strong absorption around 254 nm with negligible absorption in the visible light region. Under the joint action of the co-activation, cross-relaxation, sensitization, and phonon-assistance, color-tunable reddish-orange-yellow-green-blue emission is achieved in MgIn₂P₄O₁₄: Eu, Tb phosphors by adjusting the doping content, which demonstrates great potential for the application in fluorescent lamps.