Scalable synthesis of phosphorescent SiO2 nanospheres and their use for angle-dependent and thermoresponsive photonic gels with multimode luminescence
Changxing Wang, Yayun Ning, Yifan Yue, Guoli Du, Yuechi Xie, Jianing Li, Nazia Bibi, Xiaoxiang Wen, Jianing Li, Sen Yang, Xuegang Lu
Abstract
Abstract Developing room-temperature phosphorescent (RTP) materials with microscale periodic structures presents a promising prospect for future optical applications but remains challenging due to the complex integration of luminescent and structural components. Herein, we present a strategy for large-scale production of RTP silica nanospheres (RTP SiO 2 NPs) with a low dispersity in size using a modified Stöber method, where organic molecules are embedded in silica networks and subsequently undergo 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 gels, creating 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 fusion of physical photonic structures with luminescence offers potential approach for constructing advanced multimodal luminescent devices.