Defect-assisted dynamic multicolor modulation in KLu₃F₁₀:Tb crystals for anti-counterfeiting

KLu 3 F 10 :Tb crystals were used to realize excitation-dependent multicolor emissions. Green emissions were observed under 254 nm UV excitation, while blue emission peaking at 442 nm appeared in addition to Tb 3+ emissions under 365 nm excitation.