Fabrication, Patterning, and Optical Properties of Nanocrystalline YVO₄:A (A = Eu³⁺, Dy³⁺, Sm³⁺, Er³⁺) Phosphor Films via Sol−Gel Soft Lithography

Abstract

Nanocrystalline YVO4:A (A = Eu3+, Dy3+, Sm3+, Er3+) phosphor films and their patterning were fabricated by a Pechini sol−gel process combined with soft lithography. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric and differential thermal analysis (TG-DTA), atomic force microscopy (AFM) and optical microscopy, UV/vis transmission and absorption spectra, photoluminescence (PL) spectra, and lifetimes were used to characterize the resulting films. The results of XRD indicated that the films began to crystallize at 400 °C and the crystallinity increased with the increase of annealing temperatures. Transparent nonpatterned phosphor films were uniform and crack-free, which mainly consisted of grains with an average size of 90 nm. Patterned gel and crystalline phosphor film bands with different widths (5−60 μm) were obtained. Significant shrinkage and a few defects were observed in the patterned films during the heat treatment process. The doped rare earth ions (A) showed their characteristic emission in crystalline YVO4 phosphor films because of an efficient energy transfer from vanadate groups to them. The Sm3+ and Er3+ ions also showed upconversion luminescence in a YVO4 film host. Both the lifetimes and PL intensity of the rare earth ions increased with increasing annealing temperature from 400 to 800 °C, and the optimum concentration for Eu3+ was determined to be 7 mol % and those for Dy3+, Sm3+, and Er3+ were 2 mol % of Y3+ in YVO4 films, respectively.

White-light upconversion emission of lanthanide double-doped oxide nanoparticles via defect state luminescence of ZnO

“…The doping of Ln 3+ ions can convert the near-infrared (NIR) into visible light. The NIR excitation can penetrate the skin, which has potential biological applications, such as bioimaging and multifunctional biological probes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The white UCL has a broad range of emission wavelengths, including blue, green, and red emissions, generating a large library of spectral region that can be used for multiplexed biological labeling and encoding [16,17].…”

LaPO4:Ce,Tb and YVO4:Eu nanophosphors: Luminescence studies in the vacuum ultraviolet spectral range

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] These phosphors are characterized by their high energyconversion efficiency, purity in spectral colors, and high thermal stability. They have the advantage over the currently used sulfide phosphors in stability in vacuum and absence of corrosive gas emission under electron bombardment.…”

Luminescence Characteristics of Red Light Emitting (YVO4:Eu Thin-Film Phosphors Deposited on Si Substrate Using Pulsed Laser Deposition

“…9 Thin films of YVO 4 :Eu phosphor have been prepared by a variety of deposition techniques, such as chemical vapor deposition (CVD), 10 spray pyrolysis 11 and sol-gel method. 12 These methods suffer from either a lack of cryatallographic orientational control or the incorporation of vanadium-poor or rich nonstoichiometric phase. PLD is an attractive synthetic method for the growth of high-quality crystalline films because it is simple, relatively cheap and reliable technique, which yields high-quality films of various materials.…”