Crystal structural effects on up/down-conversion luminescence properties of GdInO3:Tm,Yb perovskite phosphors for effective dual-mode anti-counterfeit applications.
Opt Express
; 32(8): 14018-14032, 2024 Apr 08.
Article
en En
| MEDLINE
| ID: mdl-38859359
ABSTRACT
Developing advanced luminescent materials that are recognizable under specified conditions provides better opportunity for reliable optical anti-counterfeiting techniques. In this work, to the best of our knowledge, novel GdInO3Tm,Yb perovskite phosphors with ultrafine sizes and rounded morphologies were successfully synthesized by a facile chemical precipitation route. Two-type perovskites with orthorhombic and hexagonal structures could be obtained by calcining the precursor at 850 and 1100 °C, respectively. Under 980â
nm excitation, the two phosphors exhibited cyan-bluish emission at â¼460-565â
nm, red emission at 645-680â
nm, and near-infrared emission at 770-825â
nm arising from 1G4 + 1D2â3H5,6, 3F2,3â3H6, and 3H4â3H6 transitions of Tm3+, respectively, where the hexagonal perovskite phosphor had relatively strong and sharp red emission as well as red-shifted cyan-bluish emission via successive cross relaxations. The Yb3+ sensitizer enhanced the upconversion luminescence via effective Yb3+âTm3+ energy transfer and the optimal Yb3+ concentrations were 10 at.% for orthorhombic perovskite and 5 at.% for hexagonal one. The upconversion mechanism mainly ascribed to two-photon processes while three-photon was also present. Upon excitation at 254â
nm, their down-conversion spectra exhibited broad multibands in the wavelength range of 400-500â
nm deriving from combined effects of the defect-induced emission of GdInO3 and the 1D2â3F4 + 4G4â3H6 emissions of Tm3+. The energy transfer from GdInO3 defect level to Tm3+ excitation state was observed for the first time. The unclonable security codes prepared by screen printing from those dual-mode emitting perovskite phosphors were almost invisible under natural light, which had promising potential for anti-counterfeiting application.
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MEDLINE
Idioma:
En
Revista:
Opt Express
Asunto de la revista:
OFTALMOLOGIA
Año:
2024
Tipo del documento:
Article