Microstructure, luminescence and thermal stability properties of NaSrPO4:Tb3+ phosphors with various doping concentrations prepared using conventional solid-state sintering

• Novel NaSrPO4:xTb3+ phosphors prepared by solid-state sintering was investigated.
• The average particle sizes are estimated in the range of 2–8 μm.
• NaSrPO4:xTb3+ phosphor has better thermal stability than conventional YAG phosphor.

This paper reports the microstructure, luminescence and thermal stability properties of the NaSr1−xPO4:xTb3+ powders (x = 0.008, 0.01, 0.02, 0.04 and 0.06) via the conventional solid-state sintering at 1200 °C for 5 h. The X-ray diffraction result verifies all diffraction peaks are pure phase of NaSrPO4. The luminescence results show that the NaSrPO4:xTb3+ powders mainly excited at 370 nm have a series of the emission-states, related to the typical 4f → 4f intra-configuration forbidden transitions of Tb3+, and a major emission peak of around 546 nm. The concentration quenching of the NaSr1−xPO4:xTb3+ phosphors is appeared at x = 0.02. The decay time values of the NaSr1−xPO4:xTb3+ phosphors for the 5D4 state of the Tb3+ are around 3.30 ms to 3.60 ms. It is also found the chromaticity coordinate of NaSrPO4:Tb3+ phosphor varies with the increase of the concentration of Tb3+ ions from blue to green. Moreover, the thermal stability of the NaSrPO4:xTb3+ phosphors is slightly better than that of conventional YAG phosphors.