초록 close

Eu2+-activated barium magnesium silicate phosphor, (Ba,Ca)3MgSi2O8:Eux, has been known to emit blue-green light. In this study we report the manufacturing processes for producing either pure green or pure blue light-emitting phosphor from the same composition of Ba2-xCaMgSi2O8:Eux (0 < x < 1) by controlling heat treatment conditions. Green light emitting phosphor of Ba1.9CaMgSi2O8:Eu0.1 can be produced under the sample preparation condition of highly reducing atmosphere of 23% H2 / 77% N2, while blue or blue-green light emitting phosphor under reducing atmosphere of 5~20% H2 / 95~80% N2. The green light-emitting phosphors are prepared in two steps: firing at 800℃~1000℃ for 2~5 h in air then at 1100℃~ 1350℃ for 2~5 h under reducing atmosphere 23% H2 / 77% N2. The excitation spectrum of the green light-emitting phosphor shows a broadband of 300 nm~410 nm. The emission spectrum has a maximum intensity at the wavelength of about 501 nm. The CIE value of green light emission is (0.162, 0.528). The pure blue light-emitting phosphors can be produced using the Ba2-xCaMgSi2O8:Eux by introducing additional firing step at 1150~1300oC in air before the final reducing treatment. The XRD analysis shows that the green light-emitting phosphor mainly consisted of Ba1.31Ca0.69SiO4 (JCPDS # 36-1449) and other minor phases i.e., MgSiO3 (JCPDS # 22-0714) and Ca2BaMgSi2O8 (JCPDS # 31-0128). The blue light-emitting phosphor mainly consisted of Ca2BaMgSi2O8 phase.