Temperature dependence of the afterglow of persistent luminescence material SrAl2O4:Eu,Dy is a major problem for outdoor low temperature applications. Therefore this publication deals with tailoring the material for better outdoor use by exploring the second mechanism, that is involved in the afterglow – charge tunnelling from the trapping center to the luminescence center. Structure, morphology, emission and thermally stimulated luminescence properties have been measured for SrAl2O4:Eu,Dy samples with different added boron percentage. The results indicate a change in morphology of the samples with increasing boron concentration, as well as a change in afterglow times. The low temperature luminescence intensity and afterglow time dependence of boron addition turns out to be different from the room temperature luminescence intensity and afterglow time dependence from boron concentration. Boron addition in necessary amount plays a key role to creating trapping centers in the material that are located spatially close to the luminescence center thus making the material afterglow possible even in low temperatures.