Dynamic manipulation of multimodal emission in Er3+-activated non-core–shell structure for optical thermometry and information security

Regulating luminescent dynamics of lanthanide-based luminescent materials via external stimuli is of great significance in the fields of optical thermometry and high-level anti-counterfeiting. However, it is still a huge challenge to realize multimodal emissions with tunable color outputs from a single activator in simple structures via smart dynamic control of photon transition processes. Herein, we present a mechanistic strategy to achieve multimodal luminescence of Er3+ activators with color-switchable outputs in a non-core–shell host. Under the control of excitation dynamics (λex = 980, 808, 1532, 377 nm), the population among the intermediate energy levels of Er3+ and the interaction between Er3+ and Yb3+ could be precisely modulated through energy transfer and migration processes, leading to the generation of color-tunable multimodal luminescence upon diverse excitation modes (non-steady-state, single-/dual-wavelength steady, thermal activation). Inspired by its special luminescent performance, the as-obtained material exhibits great potential in noncontact thermometry, multimodal anti-counterfeiting, and high-capacity information encryption by performing a series of proof‐of‐concept experiments. Our findings might provide a conceptual model to modulate the luminescent dynamics in a simple-structured system for the generation of color-adjustable multimodal emissions, which is convenient for the development of advanced luminescent materials toward versatile cutting-edge applications.