The Luminescence Characters of High-Pressure Synthesized Europium (2)－Activated Strontium of Borate

Sr3B2O6:Eu2+, Sr2B2O5:Eu2+ and SrB4O7:Eu2+ were synthesized by the high-pressure method for the first time, and luminescence measurements of them and SrB2O4:Eu2+ were carried out. The luminescence characters were compared with those under atmosphere. The structures and emission bands of Sr3B2O6:Eu2+ and Sr2B2O5:Eu2+ have been changed due to the high pressure processing. Under an appropriate pressure (2.8 GPa) the emission intensity of SrB2O4:Eu2+ drastically increased. Its quantum efficency at the optinium excitation 313 nm is above 80 times higher than the previous one.