Epitaxial KNbO3:Yb3+,Er3+ nanopattern for enhanced upconversion photoluminescence

Achieving excitation wavelength–power-dependent colorful luminescence via multiplexing of dual lanthanides in fluorine oxide particles for multilevel anticounterfeiting

“…8a). 32,35,36 As shown in Fig. 8b, CIE coordinate of the sample (0.3188, 0.6575) is located in the green spectral region.…”

“…The excitation spectrum is predominated by five structured bands peaking at 378, 407, 451, 489 and 522 nm, ascribed to the 4 I 15/2 → 4 G 11/2 , 2 H 9/2 , 4 F 5/2 , 4 F 9/2 and 2 H 11/2 transitions of Er 3+ , respectively. 31–34 At the excitation of 378 nm, the PL spectrum shows two major peaks at 521 nm and 547 nm which are assigned to 2 H 11/2 → 4 I 15/2 , 4 S 3/2 → 4 I 15/2 transitions of Er 3+ ions, respectively (as displayed in Fig. 3b).…”

“…4 I 15/2 → 4 G 11/2 , 2 H 9/2 , 4 F 5/2 , 4 F 9/2 and 2 H 11/2 transitions of Er 3+ , respectively [31][32][33][34]. At the excitation of 378 nm, the PL spectrum shows two major peaks at 521 nm and 547 nm which are assigned to 2 H 11/2 → 4 I 15/2 , 4 S 3/2 → 4 I 15/2 transitions of Er 3+…”

Untypical tuneable emission activated by NIR radiation observed in gadolinium borate nanomaterials doped with Yb 3+ , Ho 3+ and Ce 3+ ions

“…These days, up-converting materials are broadly studied due to their exceptional spectroscopic properties, enabling them to absorb two or more low-energy photons and emit one high-energy photon 1 . This phenomenon nds numerous applications: solar cells [2][3] , biomedicine 4 , optical imaging 5 , photonic devices 6,7 , thermometric materials 8 and anticounterfeiting 9,10 . The up-conversion process can be performed using different mechanisms, which vary depending on the combinations of dopant ions and their electronic structure.…”