Intense ultraviolet upconversion luminescence of Yb3+ and Tb3+ co-doped glass ceramics containing SrF2 nanocrystals

Transparent oxyfluoride glass ceramics

“…20 [143,144]: crystals are oriented in (111) Similarly, results of the HRTEM study of SrF 2 nanocrystals [143] coincided with Fourier-transformed data of X-ray diffraction analysis of the same material (Fig. 21) and indicated that Yb 3+ , Tb 3+ and/or Er 3+ -doped SrF 2 nanocrystals had smaller crystal lattice parameters and, therefore, contained the aforementioned rare earth dopants in fluorite-type SrF 2 nanophase.…”

“…JCPDS contains data for the certain set of chemical compounds, but in practice, for example, while studying glass ceramics, researchers have to deal with phases of variable compositions that would have, in turn, variable lattice parameters and, thus, variable angles for the observed A c c e p t e d M a n u s c r i p t 26 reflection lines. Very frequently, according to the X-ray diffraction analysis data, nanoparticles formed in the glass matrices belong to the face-centered cubic fluorite-type structure [69,88,77,80,144,143,145,138], and one of the simplest examples could be the cubic M 1-x R x F 2+x (M = Ca, Sr, Ba, Pb; R = rare earth element) solid solutions that have their crystal lattice parameters changing over quite broad intervals.…”

Syntheses and optical properties of monodisperse BaLnF5 (Ln=La–Lu, Y) nanocrystals

“…Lanthanide (Ln 3+ ) doped rare earth (RE) compounds, such as oxides, fluorides, vanadates and phosphates, have gained increasing attention due to their novel electronic and optical properties arising from the 4f electrons [1][2][3][4][5][6][7], as well as their potential applications in many fields, such as vivo photodynamic therapy of cancer [8], bioimaging [9], volumetric three-dimensional displays [10] and solar cells [11]. Among them, rare earth fluorides have been widely investigated, because they possess crystal lattices of low phone energy, which decreases the non-radiative relaxation probability and thus results in relatively high luminescence efficiency for the doped Ln 3+ ions [12].…”

Upconversion luminescence from terbium and ytterbium codoped LiYF 4 single crystals

“…The study of lanthanides UC emission from infrared to visible mainly focus on Yb 3+ /RE 3+ (RE = Tb, Tm, Ho, Er) [3][4][5][7][8][9][10][11]. Those cooperative processes provided frequency UC excitation for the generation of visible light from infrared pump the donor Yb 3+ to the acceptor ion due to Yb 3+ possesses a large absorption crosssection at 980 nm [3,9].…”

“…The Yb 3+ and RE 3+ ion-pair interaction designated as cooperative energy transfer from trivalent ytterbium to RE 3+ . In this process, two or three excited Yb 3+ ions simultaneously transfer their energy to the acceptor RE 3+ ion promoting it to an excited-state level [9,10]. Several studies [3,9,11] have been reported on the spectroscopy and UC emission of Tb 3+ /Yb 3+ codoped materials.…”