Triplet–triplet annihilation upconversion combined with afterglow phosphors for multi-dimensional anti-counterfeiting and encoding

Abstract

Traditional anti-counterfeit luminescent materials were limited by the fixed excitation and emission mode. Complex anti-counterfeiting strategies with multiple luminescent modes are significantly required for defeating the continuously developing counterfeit technologies....

Nanoengineering Triplet–Triplet Annihilation Upconversion: From Materials to Real-World Applications

“…This group of materials behaves more fluidically at the nanoscale and more rigid at the macroscale due to the incorporation of long flexible side chains, thereby showing great promise for the use of integrating solid-state TTA-UC. Other materials, including poly-α-pinene (PαP) and polyisobutylene (PIB), are attractive to provide oxygen protection for solid-state TTA-UC . PαP is able to remove singlet oxygen inside the system via chemical reactions, and PIB has low oxygen permeability to further prevent external oxygen penetration.…”

“…Other materials, including poly-α-pinene (PαP) and polyisobutylene (PIB), are attractive to provide oxygen protection for solid-state TTA-UC. 218 PαP is able to remove singlet oxygen inside the system via chemical reactions, and PIB has low oxygen permeability to further prevent external oxygen penetration.…”

Biomimetic intelligent photonic crystal composite films with tri-mode optical states for advanced anti-counterfeiting and information encryption

“…In order to establish the relationship between the optical signals and the target information, a binary system was utilized to realize this goal, i.e., the ''on'' state denotes ''1'' and the ''off'' state refers to ''0''. 44 With this principle, the sprayed patterned arrays could be readily converted into binary digital codes, which represented specific ''letters'' (Fig. 5b).…”

Site occupation and upconversion process enabled multicolor emission in a Gd3GaO6:Bi3+,Er3+ phosphor for quad-mode anti-counterfeiting

“…Nowadays, anti-counterfeiting plays a significant role in the fields of banknotes, pharmaceuticals, confidential documents, jewelry, identity cards, and so on. [1][2][3][4] Generally, anti-counterfeiting labels should meet several criteria, including being lowcost, mass-produced, chemically stable, environmentally friendly, difficult to replicate, and easily identifiable using simple and portable devices. Based on these considerations, anti-counterfeiting patterns, painted with "security inks" based on luminescent materials, have attracted enormous attention.…”