Adjustable multicolor up-energy conversion in light-luminesce in Tb3+/Tm3+/Yb3+ co-doped oxyfluorifFde glass-ceramics containing Ba2LaF7 nanocrystals

Abstract

Transparent oxyfluoride glasses with highly efficient up-energy conversion (UEC) luminescence were developed in the 45SiO2-15Al2O3-12Na2CO3-21BaF2-7LaF3-xTbF3-yTmF3-zYbF3 composition (in mol%), and structural investigation by X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the formation of face-centered cubic Ba2LaF7 nanocrystals. The colors of UEC luminescences could be tuned easily by adjusting the concentration of doped rare earth ions and the excitation power of laser simultaneously. The relationship between the emission intensity of Tb3+/Tm3+/Yb3+ co-doped oxyfluoride glass-ceramics and the excitation pump power revealed that three-photon and two-photon absorptions predominated in the conversion process from the infrared into blue and red luminescences, respectively. A novel UEC mechanism of red emission from Tm3+ was proposed, energy transfers from Yb3+ to Tm3+ and Tb3+ and from Tm3+ to Tb3+ were evidenced. The possible mechanism responsible for the color variation of UEC in Tb3+/Tm3+/Yb3+ co-doped was discussed.

Energy Transfer Study on Tb3+/Eu3+ Co-Activated Sol-Gel Glass-Ceramic Materials Containing MF3 (M = Y, La) Nanocrystals for NUV Optoelectronic Devices

“…In this case, the willingly studied pathway for generation a white light is related to the mixing of three primary colors-red, green and blue (RGB)-in optical materials. Such red-green-blue multicolor visible light can be achieved via up-conversion of near-infrared radiation (NIR) [3][4][5][6][7] or via the conversion of near-ultraviolet (NUV) photons [8][9][10]. Since rare-earth ions (RE 3+ ) exhibit a broad range of emission in the visible (VIS) spectral scope via interactions with NIR and NUV irradiation, they are considered as essential parts in the development of white-light-emitting RGB materials [11,12].…”

“…Since rare-earth ions (RE 3+ ) exhibit a broad range of emission in the visible (VIS) spectral scope via interactions with NIR and NUV irradiation, they are considered as essential parts in the development of white-light-emitting RGB materials [11,12]. The first of abovementioned ways of generating RGB emission can be realized via NIR up-conversion excitation in doubly (e.g., Yb 3+ /Er 3+ [3,4], Yb 3+ /Tm 3+ [4]) and triply doped (e.g., Yb 3+ /Er 3+ /Tm 3+ [5,6], Tb 3+ /Tm 3+ /Yb 3+ [7]) optical systems. For example, for Yb 3+ /Er 3+ /Tm 3+ triply doped β-NaYF 4 microrods, Er 3+ ions are responsible for the generation of red (the 4 F 9/2 → 4 I 15/2 transition) as well as green (the 2 H 11/2 → 4 I 15/2 and the 4 S 3/2 → 4 I 15/2 transitions) emissions through a two-photon absorption process involved in Yb 3+ → Er 3+ energy transfer.…”

Controllable Photoluminescent and Nonlinear Optical Properties of Polymerizable Carbon Dots and Their Arbitrary Copolymerized Gel Glasses

“…The controlled multicolor emission of luminescent materials has attracted great interest over the past decades due to their vast applications, such as the development of light‐emitting diodes (LEDs), bioimaging, and fluorescent sensors . There are many investigations on the realization of multicolor emission, for example, by adjusting frequency up‐energy conversion, solvent or matrix, and temperature . However, it is unpredictable for fluorescence emission to use these methods.…”

Novel sol-gel SiO2-NaGdF4 transparent nano-glass-ceramics

“…In the last decades, rare-earth (RE) doped transparent oxyfluoride nano-glass-ceramics (OxGCs), where fluoride nanocrystals (NCs) are embedded in a glassy matrix, have attracted much attention. These materials can be used for several photonic applications, such as infrared and tunable phosphors, sensing, solar cells and others [1][2][3][4]. OxGCs combine excellent optical properties, due to the low phonon energy of fluoride crystals (250-450 cm −1 ), with the good chemical and mechanical properties of the oxide matrix.…”

“…OxGCs with NaGdF 4 NCs were obtained by different synthesis techniques, like melting-quenching (MQ) or solid state reaction. Moreover, NaGdF 4 NCs are known as one of the best luminescence hosts for RE ions, offering the possibility to obtain non-linear luminescence conversion using RE couples such as Yb 3+ -RE 3+ [11][12][13]. NaGdF 4 present two crystalline structures: cubic (α-phase) and hexagonal (β-phase).…”