Polyhedron engineering by chemical unit co-substitution in LaAlO3:0.02Pb2+ to generate multimode and condition-sensitive luminescence for dynamic anticounterfeiting

• Co-substitution makes the Pb 2+ ions be located in different crystal environments. • New emissions and enhanced NIR emission were found by co-substitution. • The phosphors exhibited dynamical and multimode luminescence. • They outputted inimitable and advanced signals for optical anticounterfeiting. Currently, optical responses, including photo-stimulated luminescence, thermo-luminescence, and persistent luminescence have been revealed to provide advanced security in the field of anti-counterfeiting technology. However, developing optical materials with multi-modal optical outputs is scarce but urgent. Here, a series of multimode luminescent materials of LaAlO 3 :0.02Pb 2+ were synthesized successfully via chemical unit co-substitution, with Li + -Ta 5+ , Ba 2+ -Ge 4+ and Y 3+ -Sc 3+ substituting for La 3+ -Al 3+ . The co-substitution makes the Pb 2+ ions be located in two kinds of different crystal environments, mainly due to the differences in bond length of Pb-O and geometry of PbO 12 , which are related to the changes in centroid shift, Stokes shift and crystal field splitting of Pb 2+ . Therefore, co-doping Li + -Ta 5+ , Ba 2+ -Ge 4+ and Y 3+ -Sc 3+ results in new emissions at 410 nm, 320 nm and 420 nm, respectively, along with the intrinsic emission of Pb 2+ at 460 nm. Because of the increased deep traps, co-doping Li + -Ta 5+ , Ba 2+ -Ge 4+ and Y 3+ -Sc 3+ also enhances the NIR emission, which is related to the defect-related luminescent center of V O · · - P b La ′ Meanwhile, the prepared samples show various colors at different temperatures, due to the varied thermal quenching of Pb 2+ emissions and the NIR emission. The prepared phosphors exhibited dynamical and multimode luminescence, and they outputted inimitable and advanced signals for optical anticounterfeiting, indicating that they are the potential materials for anticounterfeiting technology.