The encapsulation conditions of Eu2+-doped calcium silicon nitride ((Ca0.90Eu0.10)2Si5N8) and strontium silicon nitride ((Sr0.98Eu0.02)2Si5N8) phosphors into phosphate glass ((50-x)Na2O–xZnO–5B2O3–45P2O5; x = 10-40) were examined by pressureless sintering (normal or infrared firing) and subsequent oxygen-assisted hot isostatic pressing. The evaluation of water resistivity, as well as glass transition temperature (Tg), indicated that the excellent water resistivity and low Tg (313°C) could be achieved at x = 30. The colorless and clear glass body could be fabricated by infrared firing at 370°C for 20 minutes in air, followed by the hot isostatic pressing at 370°C for 24 hours (80%Ar + 20%O2, pressure: 130 MPa). The encapsulations of 3.0 mass% (Ca0.90Eu0.10)2Si5N8 and (Sr0.98Eu0.02)2Si5N8 into the glass body produced reddish orange light emission (peak wavelength: 604 nm under excitation wavelength of 423 nm) and red-light emission (617 nm under 383 nm), respectively, showing higher chemical and thermal stability of nitride phosphors in the glass matrix.
- hot isostatic pressing