Luminescent properties of Eu2+-activated (Sr1-z, Caz)(Al1-y, By)2O4 phosphors for UV LEDs

•(Sr1−z, Caz)(Al1−y, By)2O4: xEu2+ phosphors were synthesized by sol–gel process.•For Sr(Al1.98, B0.02)O4:Eu2+, the optimum reducing temperature and Eu2+ concentration was 1200°C and 8%.•Doping higher B3+ induced the phase transform, resulting in the obvious blue-shift from 518 to 467nm.•Ca instead of the Sr atoms forms Sr–Ca solid solution and exhibited the 518nm green and 440nm blue emission.