Design of hierarchical composite silicate for full-color and high thermal stability phosphors

Design of new hollow structure materials with high complexity in shell architecture and composition has been proven to be an efficient strategy to improve their properties in many applications. Herein we devise and demonstrate a general strategy to synthesize composite silicate with hierarchical hollow structure: (1) coating mesoporous silica on precursor; then (2) treated with proper solution on certain conditions, and then (3) thermal treatments. By using Y(OH)CO3 submicrospheres as precursor, hollow composite silicate (Y2Si2O7@Zn2SiO4) has been fabricated successfully. This Y2Si2O7@Zn2SiO4 structure can accommodate multifold luminescent activator ions (Ce3+, Mn2+, Eu3+) and realize full-color luminescence under a single wavelength excitation. Moreover, the emission of Ce3+, Eu3+ and Mn2+ in Y2Si2O7@Zn2SiO4 structure exhibit excellent luminescence thermal stability due to the generation of defects at the interface and efficient energy transfer from the defect levels to activators at higher temperature. This novel fabrication methodology provides a feasible way to achieve multi-component hollow structure with multi-color emission for application in solid-state lighting, which is not limited to Y2Si2O7@Zn2SiO4 material, but applying to other material systems.