Upconversion Luminescence Properties of Yb<SUP>3+</SUP> and Tm<SUP>3+</SUP> Codoped Amorphous Fluoride ZrF<SUB>4</SUB>–BaF<SUB>2</SUB>–LaF<SUB>3</SUB>–AlF<SUB>3</SUB>-NaF Thin Film Prepared by Pulsed Laser Deposition

Abstract

The Yb3+ and Tm3+ co-doped 55.98ZrF4-28BaF2-2.5LaF3-4AlF3-7NaF-2.5YbF3-0.02TmF3 amorphous fluoride film was prepared by pulsed laser deposition. The spectroscopic properties and energy transfer analysis of this film were studies in detail. Ultraviolet and visible upconversion emissions were observed under the infrared excitation at 980 nm. In comparison with that of its target, the upconversion emissions of the film in the visible and ultraviolet range were greatly enhanced. The possible energy transfer mechanism of the emissions was given to understand the upconversion process. This kind of thin films has potential applications for the integrated optical waveguide amplifier and ultraviolet laser.

Ultraviolet Upconversion Luminescence in a Highly Transparent Triply-Doped Gd3+–Tm3+–Yb3+ Fluoride–Phosphate Glasses

“…Owing to their unique and simple energy level diagram with only a single transition ( 2 F 7/2 → 2 F 5/2 ), ytterbium ions are frequently introduced as sensitizer centers at ∼1 μm pumping wavelength, producing large enhancements of UC luminescence of Tm 3+ ions activators. Thus, efficient UV UC emissions induced by near-IR light have been reported for some Tm 3+ –Yb 3+ codoped materials. − Owing to the large energy gap (32 000 cm –1 ) separating the Gd 3+ ground state 8 S 7/2 and the first excited state 6 P 7/2 , Gd 3+ levels cannot be populated directly by IR pumping. On the other hand, introduction of Gd 3+ to Tm 3+ –Yb 3+ codoped materials can provide additional UV UC emissions, important for building UV compact devices. ,,− Four UC emission peaks of Gd 3+ were observed in the range 190–210 nm, one at 253 nm, − three in the range 270–281 nm, − and one at 311 nm − involving up to seven photons processes.…”

Near-Infrared Upconversion Transparent Inorganic Nanofilm: Confined-Space Directed Oriented Crystal Growth and Distinctive Ultraviolet Emission

“…In recent years, self-assembly films with UCNPs have been reported and has attracted many researchers’ interest. , However, the hard to be extended assembly area and weak adhesion have limited their further development. One-step synthesis of UC films is also reported such as by pulsed laser deposition and molecular beam epitaxy, which however demand expensive devices. UC films prepared by electrodeposition − are popular and can alleviate these problems, but still have some drawbacks such as selective ITO substrates and unreachable UC fluorescence until prior annealing at a high temperature. , Therefore, to further improve properties of composite UC films and explore their novel and intrinsic functions, it is necessary to develop a new and simple one-step preparation approach to meet demands of at least inexpensive, robust, available fluorescence and additionally transparent, controllable growth.…”

“…15,16 However, the hard to be extended assembly area and weak adhesion have limited their further development. One-step synthesis of UC films is also reported such as by pulsed laser deposition 18 and molecular beam epitaxy, 19 which however demand expensive devices. UC films prepared by electrodeposition 20−22 are popular and can alleviate these problems, but still have some drawbacks such as selective ITO substrates and unreachable UC fluorescence until prior annealing at a high temperature.…”

“…UC films prepared by electrodeposition 20−22 are popular and can alleviate these problems, but still have some drawbacks such as selective ITO substrates and unreachable UC fluorescence until prior annealing at a high temperature. 18,22 Therefore, to further improve properties of composite UC films and explore their novel and intrinsic functions, it is necessary to develop a new and simple one-step preparation approach to meet demands of at least inexpensive, robust, available fluorescence and additionally transparent, controllable growth. In our work, an easily constructed confined space between superimposed silica glass substrates which only demands cleaning with ethanol is utilized to fabricate a composite inorganic UC nanofilm characteristic as transparent, robust, oriented, and controllable of morphology based on a hydrothermal reaction.…”

Current Approaches to Light Conversion for Controlled Environment Agricultural Applications: A Review

“…To date, a large number of such luminophores have already been developed; for example, the NaYF 4 :YbEr luminophore, which converts near-IR (976 nm) to green (534 nm and 549 nm) and red light (654 nm) [141]. Covers containing phosphors based on Yb 3+ and Tm 3+ are excited by NIR illumination (980 nm) and luminesce at 474 nm with FWHM 40 nm, 646 nm with FWHM 10 nm and 803 nm with FWHM 50 nm [142]. Such materials can apply to amplify waveguides.…”