Scalable Synthesis of Self-Assembling Monodisperse Phosphorescent Nanospheres Enabling Multi-Mode Angle-Dependent and Thermal-Responsive Photonic Gels

Developing room-temperature phosphorescent (RTP) materials with microscale periodic structures presents a promising prospect for future optical applications but remains extremely challenging due to the complex integration of luminescent and structural components. Herein, we present an emerging strategy for mass-producing monodisperse RTP silica nanospheres (RTP SiO ₂ NPs) using a modified Stöber method, where organic molecules are embedded in silica networks and undergone in situ carbonization, aggregation and crystallization to form phosphorescent carbon dots under high temperature calcination. These NPs can self-assemble into photonic crystal (PC) structures, enabling the straightforward integration of structural color, fluorescence (FL) and RTP to achieve multimodal luminescent properties. The angle-dependent photonic bandgap (PBG) generated by the physical periodic structure modulates light propagation in RTP PC gel, creating unique FL and RTP angle-dependent chromatic responses. Temperature-induced refractive index changes between SiO ₂ and the liquid matrix further enable dynamic control of light scattering states, significantly altering transmittance and emission intensities of FL and RTP. This successful fusion of physical photonic structures with chemical luminescence offers new approach for constructing advanced multimodal luminescent devices.