Red to Blue Tunable Upconversion in Tm³⁺-Doped ZrO₂ Nanocrystals

Abstract

The effect of dopant concentration on the blue upconversion (UPC) emission of Tm(3+) -doped ZrO(2) nanocrystals under different excitation wavelengths in the red region is reported. The UPC emissions are due to the f-f electronic transitions from excited states (1)G(4) and (1)D(2) of Tm(3+). We observed a chromatic change in the UPC with tuning the excitation wavelength. The UPC emission bands at 475, 488, and 501 nm are observed under excitation at 649 nm, but bands centered at 454 and 460 nm are observed when the excitation wavelength is tuned to 655 nm. The UPC emission could be tuned from 501 to 454 nm ( approximately 47 nm) by changing the excitation wavelength from 649 to 655 nm ( approximately 6 nm). The pump power dependence of the emission bands at 475, 488, and 501 nm were investigated on excitation intensity at 649 nm, and the emission bands at 454 and 460 nm are investigated on excitation intensity at 655 nm, which confirms that all of these UPC emission lines are a two-photon absorption process.

Lanthanide‐Doped Nanocrystals: Strategies for Improving the Efficiency of Upconversion Emission and Their Physical Understanding

“…3 H 6 transition. [61] The crystal field effect due to the host lattice was the main reason to split this 3 H 6 , the transition was stronger at an excitation wavelength of l = 649 nm, whereas emission for the 1 D 2 ! 3 H 5 transition dominated at an excitation wavelength of l = 655 nm.…”

“…The sol-emulsion-gel method has also been used by for the preparation of Tm 3 + -doped ZrO 2 nanoparticles. [61] Alencar et al [62] used barium acetate, titanium isopropoxide, and erbium acetate as the starting materials for the sol-gel preparation of Er 3 + -doped BaTiO 3 nanoparticles. The coprecipitation method is also one of the simplest and most convenient approaches for synthesizing rare-earth-based upconverted nanocrystals.…”

Nanocrystalline lanthanide-doped Lu3Ga5O12garnets: interesting materials for light-emitting devices

“…In figure 10 a schematic representation of the expected upconversion processes populating the 1 [52]. An upconversion emission in the 470-510 region was also observed for a Tm 3+ -doped ZrO 2 nanocrystalline sample, upon excitation at 649 nm [53]. For the sake of comparison with other Tm 3+ -doped nanocrystalline garnets, we measured the upconversion emission in the same experimental conditions (such as pump power and measurement geometry) for Tm 3+ doped nanocrystalline GGG prepared with the same sol-gel citric acid procedure [54].…”

Ultimately simple one-pot single-step synthesis of rare earth doped spherical mesoporous metal oxide nanospheres with upconversion emission ability in supercritical methanol

“…Consequently, these NPs have attracted much attention for their potential applications in optical communications, optoelectronic devices, flat panel displays, photodynamic therapy, and biosensors [3][4][5][6][7][8][9][10]. Several RE dopants, such as Er 3+ [11][12][13][14][15][16], Eu 3+ [17][18][19], Sm 3+ [20,21], Tm 3+ [22], and Ho 3+ [23], have been utilized as luminescent centers. To reduce multiphonon relaxation and concentration quenching, the host materials of the UCNPs fixing the dopant in the appropriate position should be carefully selected.…”

“…Metal oxides are one of the best host materials for RE ions because many of them, such as CeO 2 , ZrO 2 , TiO 2 , etc. are highly transparent to visible light and possess strong mechanical, optical, and thermal stabilities and properties [11][12][13][14][15][16][17][18][19][20][21][22]. and high-resolution transmission electron microscopy images were taken using JEOL JEM-2100F.…”