Enhancement of Visible Upconversion Emission in Y₂O₃:Er³⁺‐Yb³⁺ by Addition of Thiourea and LiOH in the Phosphor Synthesis

Abstract

Spherical like Y2O3nanostructures doped with Er3+and Yb3+ions have been synthesized by a facile hydrothermal method. The samples were prepared by using different precipitant agents in the synthesis process. The phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence spectroscopy. Effects of the precipitant agents on structural, morphological, and photoluminescence properties of Y2O3:Er3+-Yb3+are studied and discussed. XRD analysis indicates that all samples, prepared with different precipitant agents, present the same cubic phase. Electron microscopy measurements show regular spherical shapes with size diameter depending on precipitant agent. Photoluminescence reveals that the samples have strong green (563 nm) and red (660 nm) emissions corresponding to4S3/2 → 4I15/2and4F9/2 → 4I15/2transitions of Er3+ions, respectively. The nanophosphors prepared with both Thiourea and Lithium Hydroxide exhibit the stronger visible upconversion luminescence under 980 nm diode laser excitation.

The Quality Improvement of Yttrium Oxide Thin Films Grown at Low Temperature via the Third‐Generation Mist Chemical Vapor Deposition Using Oxygen‐Supporting Sources

“…All four samples had broad bands around 3500, 1502, and 1402 cm −1 corresponding to the OH [ν(OH) group], C=O [ν(C=O) group], and CH 3 [ν(CH 3 ) group] stretching vibrations, respectively. [ 12,14,33 ] It was concluded that the bonds related to the ν(OH) group originated from H 2 O, whereas the ν(C=O) and ν(CH 3 ) groups originated from the Y(acac) 3 precursor. Interestingly, sample C, which was fabricated with H 2 O support only, showed the lowest absorbance intensity originated from the ν(O–H), ν(C=O), and ν(CH 3 ) bonds.…”

“…The yttrium oxide (Y 2 O 3 ) thin film has obtained significant attention due to its excellent properties, such as high dielectric constant (14)(15)(16)(17)(18)(19)(20), large bandgap (%5.5 eV), relatively high refractive index (1.7-1.9), low absorption (from near-UV to IR region), and high melting point (%2439 C). [1][2][3][4] These characteristics make Y 2 O 3 a promising material in the fields of microelectronics, waveguide, ferroelectrics, and superconductors.…”

“…According to previous works, Y 2 O 3 thin films are prepared by not only nonequilibrium reaction processes, for instance, electron-beam deposition and pulsed-laser deposition, [8,9] but also equilibrium ones, such as metal-organic chemical vapor deposition and atomic layer deposition. [10,11] However, many studies have shown that the high growth temperature, [10,12] long subsequent treatment, [13] and/or specific formation-assisted processes [11,14] are necessary for obtaining high-quality Y 2 O 3 thin films, which limits the large-scale applications of this material.…”

Size‐Controllable Synthesis of Submicro Spherical Yttrium Carbonate and In Situ Doping of Europium to Prepare Y2O3: Eu3+ Phosphor

“…The synthesis of Y 2 O 3 microspheres has drawn intensive interests in recent years. Several approaches such as hydrothermal method, [ 1 ] combustion method, [ 2 ] spray pyrolysis method, [ 3 ] precipitation method, [ 4 ] microwave assisted synthesis methods, [ 5 ] and sol–gel method [ 6 ] were employed to synthesize spherical Y 2 O 3 . However, some drawbacks such as the agglomeration, nonuniform size distribution, or uncontrollable particle size of obtained Y 2 O 3 microspheres still are the challenges for engineers and researchers.…”