Luminescence centers in thin films of yttrium oxide and yttrium-aluminum garnet activated with bismuth

Abstract

with maxima at 3.03 eV and 3.15 eV, respectively, that is related to the 3 P 1 -1 S 0 transition. The emission of Bi 3+ in the site with point symmetry C 2 gives green luminescence in Y 2 O 3 :Bi with the maximum at 2.40 eV that is also related to the 3 P 1 -1 S 0 transition. The emission of Bi 3+ in the site with point symmetry D 2 leads to ultraviolet luminescence in Y 3 Al 5 O 12 :Bi with the maximum at 3.75 eV that corresponds to the 3 P 1 -1 S 0 transition. The red luminescence band with the maximum at 1.85 eV in Y 2 O 3 :Bi is due to the presence of structural defects.Introduction. Luminophores based on yttrium oxide Y 2 O 3 and yttrium-aluminum garnet Y 3 Al 5 O 12 are promising materials for electronics and scintillation and laser technology [1,2]. Such luminophores activated by ions of rare-earth elements are especially common. Moreover, Y 2 O 3 and Y 3 Al 5 O 12 activated by another group of important activators, the so-called mercury-like ions, of which Bi 3+ is one, are poorly studied [3,4]. Thin films of such compounds can be used as scintillators in luminescent screens or mercury-free luminescent photomultiplier bulbs. The spectral properties of these materials have been well studied [3][4][5][6][7]. However, many questions of scientific interest have not been finally resolved. These concern establishing the nature of the luminescence centers and their interaction with processes occurring in the excited lattice. Therefore, the investigation of thin films of Y 2 O 3 and Y 3 Al 5 O 12 is timely and addressed herein.Experimental. Thin films of Y 2 O 3 :Bi and Y 3 Al 5 O 12 :Bi were prepared by separate vaporization in vacuo on a fused quartz substrate. Sputtered films were annealed in air at 900-950 o C for 3-4 h. The content of Bi 3+ activator was 0.5-1.0 mol %. X-ray diffraction showed a polycrystalline structure with primary orientation in planes (222), (400), and (440) for Y 2 O 3 :Bi films and (400), (420), and (521) for Y 3 Al 5 O 12 :Bi films.Luminescence excitation and photoluminescence (PL) spectra of thin films of Y 2 O 3 :Bi and Y 3 Al 5 O 12 :Bi and luminescence spectra upon x-ray and laser excitation of Y 2 O 3 :Bi films were investigated. The photoexcitation source was a DKsEl-1000 lamp with ZMR-3 monochromator; the x-ray excitation source, an URS-55A (Russia) unit with a copper anode (40 kV, 2-12 mA). Luminescence upon laser excitation was studied using pulsed excitation by radiation from a LGI-21 laser (Ukraine) with λ ex = 337.1 nm. Emission of samples was analyzed using a SF-4A monochromator and recorded using an FÉU-51 (Russia) photomultiplier, the signal from which was fed through an amplifier into a PDA-1 recorder (Ukraine). An automatically regulated monochromator slit kept the number of quanta constant during the study of excitation spectra. A correction for the photodetector sensitivity was applied for luminescence spectra.Results and Discussion. Previous investigations of Y 2 O 3 :Bi ceramic [5][6][7] showed that the luminescence spectra contained at least two emission bands wi...

Effect of Bi2O3 proportion on physical, structural and electrical properties of zinc bismuth phosphate glasses

“…The UV emission peak centered at 368 nm is ascribed to 3 P 1 → 1 S 0 transition of Bi 3+ ions D 2 site symmetry [24]. increase in Bi 2 O 3 concentration, but the decrease in PL intensity (B 4 to B 5 ) indicates the decrease of Bi 3+ ions at higher concentration.…”

Structural, Morphological and Optical Study of Bismuth and Zinc Co-Doped Yttrium Oxide Prepared by Solvothermal and Wet Chemical Method

“…Yttrium oxide (Y 2 O 3 ) is the most familiar yttrium compound, which is popularly known as host for ion doping of other rare earth elements. Luminophores based on Y 2 O 3 are promising materials for electronics and scintillation and laser technology [1,2]. Such luminophores activated by ions of rare-earth elements are especially common.…”

“…Such luminophores activated by ions of rare-earth elements are especially common. Moreover, Y 2 O 3 activated by another group of important activators, like zinc and the so-called mercury-like ions, of which bismuth ion (Bi 3+ ) is one, are poorly studied [2,3]. Such compounds can be used as scintillators in luminescent screens or mercury-free luminescent photomultiplier bulbs.…”