SiAlON-based crystal–glass composite phosphor with tunable yellow-green-blue color emission induced by SiO2 melting corrosion

Abstract

SiAlON-based crystal–glass composite phosphors with tunable yellow-green-blue emission are exploited. Substitution of Al–N by Si–O in a SiAlON lattice and the introduction of a Si–Al–O–N glass phase are induced by melting corrosion as SiAlON polycrystal powders were heat-treated with nano-SiO₂ additive. The melting corrosion process involving liquid penetration, solid dissolution, liquid transportation is discussed and assigned to the origin of morphology transformation. The substitution extent and the glass content are identified to increase with the addition of nano-SiO₂ additive. The resultant tunable photoluminescence of Eu²⁺ in the SiAlON lattice and Si–Al–O–N glass matrix and the microstructure evolution are detailed, respectively. The emission color of the SiAlON-based crystal–glass composite phosphors is traced continuously from yellow to green then to blue with the combination of changeable emissions of Eu²⁺ originated from the SiAlON phase and glass phase. This artful SiAlON-based crystal–glass composite phosphor shows flexible color-adjustable capability with the control of SiO₂ melting corrosion, indicating the potential applications in lighting and display fields.