Study of the Electronic Structure and Optical Properties of Rare Earth Luminescent Materials

Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properties of rare earth luminescent materials, with the goal of uncovering their importance in luminescence mechanisms and applications. Through theoretical calculations and experimental methods, we conducted in-depth analyses on materials composed of various rare earth elements. Regarding electronic structure, we utilized computational techniques such as density functional theory to investigate the band structure, valence state distribution, and electronic density of states of rare earth luminescent materials. The results indicate that the electronic structural differences among different rare earth elements notably influence their luminescence performance, providing crucial clues for explaining the luminescence mechanism. In terms of optical properties, we systematically examined the material’s optical behaviors through fluorescence spectroscopy, absorption spectroscopy, and other experimental approaches. We found that rare earth luminescent materials exhibit distinct absorption and emission characteristics at different wavelengths, closely related to the transition processes of their electronic energy levels. Furthermore, we studied the influence of varying doping concentrations and impurities on the material’s optical properties. Experimental outcomes reveal that appropriate doping can effectively regulate the emission intensity and wavelength, offering greater possibilities for material applications. In summary, this study comprehensively analyzed the electronic structure and optical properties of rare earth luminescent materials, providing deep insights into understanding their luminescence mechanisms and potential value in optoelectronic applications. In the future, these research findings will serve as crucial references for the technological advancement in fields such as LEDs, lasers, and bioimaging.

Atomic layer deposition in advanced display technologies:from photoluminescence to encapsulation

Driven by the growing demand for next-generation displays,the development of advanced luminescent materials with exceptional photoelectric properties is rapidly accelerating,with such materials including quantum dots and phosphors,etc.Nevertheless,the primary challenge preventing the practical application of these luminescent materials lies in meeting the required durability standards.Atomic layer deposition(ALD)has,therefore,been employed to stabilize luminescent materials,and as a result,flexible display devices have been fabricated through material modification,surface and interface engineering,encapsulation,cross-scale manufacturing,and simulations.In addition,the appropriate equipment has been developed for both spatial ALD and fluidized ALD to satisfy the low-cost,high-efficiency,and high-reliability manufacturing requirements.This strategic approach establishes the groundwork for the development of ultra-stable luminescent materials,highly efficient light-emitting diodes(LEDs),and thin-film packaging.Ultimately,this significantly enhances their potential applicability in LED illumination and backlighted displays,marking a notable advancement in the display industry.

In situ luminescence measurements of GaN/Al_(2)O_(3) film under different energy proton irradiations

Ion beam-induced luminescence(IBIL) experiments were performed to investigate the in situ luminescence of GaN/Al_(2)O_(3) at varying ion energies,which allowed for the measurement of defects at different depths within the material.The energies of H^(+)were set to 500 keV,640 keV and 2 MeV,the Bragg peaks of which correspond to the GaN film,GaN/Al_(2)O_(3) heterojunction and Al_(2)O_(3) substrate,respectively.A photoluminescence measurement at 250 K was also performed for comparison,during which only near band edge(NBE) and yellow band luminescence in the GaN film were observed.The evolution of the luminescence of the NBE and yellow band in the GaN film was discussed,and both exhibited a decrease with the fluence of H^(+).Additionally,the luminescence of F centers,induced by oxygen vacancies,and Cr^(3+),resulting from the ^(2)E →^(4)A_(2) radiative transition in Al_(2)O_(3),were measured using 2 MeV H^(+).The luminescence intensity of F centers increases gradually with the fluence of H^(+).The luminescence evolution of Cr^(3+)is consistent with a yellow band center,attributed to its weak intensity,and it is situated within the emission band of the yellow band in the GaN film.Our results show that IBIL measurement can effectively detect the luminescence behavior of multilayer films by adjusting the ion energy.Luminescence measurement can be excited by various techniques,but IBIL can satisfy in situ luminescence measurement,and multilayer structural materials of tens of micrometers can be measured through IBIL by adjusting the energy of the inducing ions.The evolution of defects at different layers with ion fluence can be obtained.

Luminescent properties of Lu_2MoO_6:Eu^(3+) red phosphor for solid state lighting

The Eu^3＋ activated Lu2MoO6 phosphors were synthesized by high-temperature solid-state reaction method. The X-ray diffraction （XRD）, excitation spectra, emission spectra and decay lifetime of the phosphors were measured to characterize the structure and luminescent properties. The XRD results show that all the prepared phosphors can be assigned to the monoclinic structure. The experimental results indicate efficient absorption of near ultraviolet light from the Mo^6＋O^2- group followed by intensive emission in the visible spectral range. The optimal content of Eu3＋ is 10% （mole fraction）. The critical distance Rc and energy transfer mechanism were also discussed in detail. This red emitting material may be applied as a promising red phosphor for the near ultraviolet excited white light emitting diodes.

Synthesis, Characterization and Luminescent Properties of La2Zr2OT：Eu3＋ Nanorods

The Eu3＋-doped La2Zr207 phosphor with rod-like morphology was successfully synthesized by conventional solid state reaction and hydrothermal method. X-ray diffraction patterns, transmission electron microscopy, and photoluminescence spectra were employed to charac- terize its structure and morphology as well as luminescent properties. The results indicated that the red-emitting phosphor La2Zr207：Eu3＋ had well crystallized and belonged to the cubic structure with space group of Fd3m. The as-obtained product mainly appeared as straight nanorods with an average diameter of 47 nm and length of 50-700 nm. The pos- sible growth mechanism was also discussed. It was found that under blue excitation with a wavelength of 466 nm, the La2Zr2OT：Eu3＋ phosphor exhibited a characteristic red emission at 616 nm that was attributed to the hypersensitive 5D0--＊TF2 electric dipole transition of Eu3＋ ions. Meanwhile, it was more interesting to note that the emission of 5D1--＊TFj （J=0, 1, 2） transitions and the splitting patterns of 5D0---＋TFJ （J--l, 2, 4） transitions of Eu3＋ ions can be observed in the luminescent spectra of La2Zr207：Eu3＋. It was demonstrated that Eu3＋ preferred to occupy a low symmetry site.

Cultural and luminescent Conditions of a Marine luminous Bacterium

Study of marine noctilucence in marine is important to fishery, environmental monitoring and military affairs. A luminous bacterial strain D2 was isolated from the marine sediment samples collected near Donghai Island in Zhanjiang, China. The primary cultural and luminescent conditions of luminous bacterium D2 which was identified as Vibrio sp. were determined in liquid culture. The results showed that pH 7.0, 35 ℃, with 2.0 % NaCI, were the best growth conditions, and pH5 - 6, 20℃, OD600 0.08, with 3.0 % NaCI, were the optimal luminescent conditions.

Photoluminescent properties of LaF_3:Eu^(3+) and GdF_3:Eu^(3+)nanoparticles prepared by co-precipitation method

GdF3：Eu^3＋ and GdF3：Eu^3＋ nanoparticles were prepared by a co-precipitation method in the presence of the chelating agent, citric acid. The structural properties of the products were characterized by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. The average crystallite size was estimated from the full-width at half-maximum （FWHM） of the diffraction peaks by the Scherrer equation. The sizes of the nanoparticles were 12 nm for LaF3：Eu3＋ and 17 nm for GdF3：Eu^3＋. The luminescent properties of the nanoparticles were investigated by excitation and emission spectra. Energy transfer from Gd3＋ to Eu3＋ was observed.

Preparation and properties of RE^(3+) doped luminescent co-polymer by solution copolymerization

Bonded type RE3+ doped luminescent co-polymer was synthesized by solution free radical copolymerization. The influence of charge sequence, monomers and co-polymerized method on properties and structures of the co-polymers was studied. The emission intensity of the co-polymers at different RE3+ concentrations was tested. The results showed that the co-polymers of Eu-PSt and Eu-PMMA both had wide absorption peak at 200-400 nm and the strongest peak appeared at 235 nm. The fluorescent intensity of Eu3+ doped polystyrene co-polymer was stronger than that of Eu3+ doped PMMA copolymer. The characteristic emission of europium ions was observed in the co-polymers. The copolymer doped with rare earth elements showed the 'sensitization effect' for the central ions. The bonded-type rare earth copolymer not only enhanced the energy transfer efficiency, but also improved the fluorescence intensity by increasing the rigidity of main and side chain.

Synthesis, Crystal Structure and Luminescent Property of the One-dimensional Chain Chlorodibenzyltin 2-Quininate

A one-dimensional chain chlorodibenzyltin 2-quininate has been synthesized and characterized by IR, NMR spectra and elemental analysis. The crystal structure has been determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group I4（—） with a = 19.1171（10）, b = 19.1171（10）, c = 12.5158（6） , Z = 8, V = 4574.1（4） 3, Dc = 1.477 g·cm-3, μ（MoKα） = 1.252 mm-1, F（000） = 2032, R = 0.0259 and wR = 0.0723. In the complex, the tin atom is six-coordinated to adopt a distorted octahedral configuration with bridging carboxyl of quinoline-2-carboxylic acid. The result of fluorescence spectrum analysis shows that the title complex at room temperature exhibits an intense photoluminescence with maximum emission at 364.2 nm （λex = 303.0 nm）.

Synthesis,luminescent properties,and theoretical study of novel Sm^(3+) and Dy^(3+) complexes containing β-diketone and 1,10-phenanthroline

Two new ternary complexes of 1-（2-thienyl）-3-（p-phenylethynylphenyl）-1,3-propanedione（HTPP） and 1,10-phenanthroline（phen） with Sm^3＋ and Dy^3＋ were synthesized.The composition of the ternary complexes was characterized as Sm（TPP）3phen and Dy（TPP）3phen,respectively,by infrared（IR） spectra,chemical analysis,elemental analysis,and thermodynamic analysis.At room temperature,under UV light excitation,the Sm^3＋ and Dy^3＋ complexes exhibit characteristic emissions of the central ions.It is found that the fluorescence intensity of Sm（TPP）3phen is stronger than that of Dy（TPP）3phen.In order to explain this phenomenon,an accurate quantum chemistry calculation was carried out,and the result is in good agreement with the experiment data.

Synthesis, Structure, and Luminescent and Dielectric Properties of a Novel 1D Chain Zinc(Ⅱ) Complex {[Zn(DCImPyO)·(H_2O)_2·]·H_3O}_n

Under hydrothermal conditions, 4-（4,5-dicarboxy-lH-imidazol-2-yl）pyridine 1-oxide （H3DCImPyO） reacted with ZnC12 to give the 1D chain complex {[Zn（DCImPyO）·（H2O）2·]·H3O}n （1）. Single-crystal X-ray determination shows that complex 1 crystallizes in the monoclinic system, space group P21/c with a = 9.488（2）, b = 13.247（3）, c = 12.959（4） A, β = 126.716（19）°, Z = 4, V= 1305.6（6）/k3, C10H11N3O8Zn, Dc = 1.865 g/cm3, Mr = 366.61, 2（MoKa） = 0.71073 A, μ= 1.930 mm1, F（000） = 744, R = 0.0472 and wR = 0.1487. Fluorescent analysis showed an intense emission band at 422 nm when the exciting radiation was set at 378 nm. Dielectric constant of complex 1 was measured at different frequencies with temperature variation.

Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a Zinc(II) Coordination Polymer Assembled by Phthalate and 4,4′-Bipyridine

A metal-organic coordination polymer {[Zn（Pht）（4,4＇-bipy）（H2O）2]·2H2O}n （Pht = phthalate, 4,4＇-bipy = 4,4＇-bipyridine） 1 has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. Yellow crystals crystallize in the monoclinic system, space group P2/n, a = 7.6346（14）, b = 11.316（2）, c = 10.8133（19） ,A, β = 92.A.A,A.（3）°, V = 933.3（3） A^3, C18H20N2O8Zn, Mr = 457.73, Dc = 1.629 g/cm^3, F（000） = 472, Z = 2,μ（MoKa） = 1.367 mm^-1, the final R = 0.0323 and wR = 0.0821 for 1859 observed reflections （Ⅰ〉 2σ（Ⅰ））. The structure of 1 exhibits a two-dimensional bilayer framework formed by hydrogen bonding interactions. Furthermore, 1 shows yellow photoluminescent property at room temperature.

Hydrothermal Synthesis, Crystal Structure and Photoluminescent Property of a New Isophthalate- bridged Zinc(II) Polymer with One-dimensional Chain Structure: [Zn(ipt)(im)_2]_(2n)·3nH_2O (ipt = Isophthalate, im = Imidazole)

A new metal-organic coordination polymer [Zn（ipt）（im）2]2n·3nH2O 1 has been obtained by using hydrothermal synthesis and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P2（1/n） with a = 10.653（3）, b = 17.891（6）, c = 10.743（4）A^°,β= 117.093（5）°, V= 1822.9（10） A^°3, Mr= 413.65, Dc = 1.507 g/cm^3,/t（MoKa） = 1.390 mm^-1, F（000） = 840, Z = 4, the final R = 0.0444 and wR = 0.1066 for 2434 observed reflections （I〉 2σ（I））. Furthermore, compound 1 shows blue photoluminescent property at room temperature.

Synthesis, Structure and Luminescent Property of a 2D Cd(Ⅱ) Coordination Polymer Based on Mixed-ligands of 1,3-Bis(imidazol)propane and Pyridine-3,5-dicarboxylic Acid

A new Cd（Ⅱ） coordination polymer, namely, [Cd（1,3-bip）（3,5-pdc）]n （1,3-bip = 1,3-bis（imidazol）propane and 3,5-pdc = pyridine-3,5-dicarboxylic acid） has been synthesized under hydrothermal conditions. Compound 1 was characterized by infrared spectrum, elemental analysis, powder X-ray diffraction （PXRD） and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic, space group P21/c with a = 1.40178（7）, b = 1.72502（12）, c = 1.41635（6） ran, β = 92.653（4）°, V = 3.4212（3） nm3, Z = 4, C16HIsCdNsO4, Mr = 453.73, Dc = 1.762 g/cm3, F（000） = 1808,μ = 1.310 mm1, R = 0.0899 and wR = 0.1945. In compound 1, each 3,5-pdc ligand links three Cd（lI） ions and each Cd（Ⅱ） attaches to bip ligands to form a complicated 2D double-layer structure. In addition, the thermal stability and luminescent property of 1 have been studied in the solid state at room temperature.

Luminescent characteristics of Ba_3Y_2(BO_3)_4:Eu^(3+) phosphor for white LED

The Ba3Y2（BO3）4：Eu^3＋ phosphor was synthesized using a high temperature solid-state reaction method and the luminescent characteristics were investigated. The emission spectrum exhibited one strong red emission at 613 nm, corresponding to the electric dipole 5D0-TF2 transition of Eu^3＋, under 365 nm excitation. The excitation spectrum of 613 nm indicated that the Ba3Y2（BO3）n：Eu^3＋ phosphor was effectively excited by ultraviolet （UV） （254, 365 and 400 nm） and blue （470 nm） light. The effect of Eu^3＋ concentration on the 613 nm emission of the Ba3Y2（BO3）n：Eu^3＋ phosphor was measured. The results showed that the emission intensity increased with increasing Eu^3＋ concentration, and then decreased. The CIE color coordinates of Ba3Y2（BO3）4：Eu^3＋ phosphor were x=0.641 and y=0.359 at 15 mol.% Eu^3＋.

Synthesis, Crystal Structure and Luminescent Property of a Ag(Ⅰ) Coordination Polymer with a 3D Sandwich-like Framework

A new coordination polymer,{[Ag2（bpp）2（H2O）2]·bpdc·3H2O}n,derived from the ligand biphenyl-4,4＇-dicarboxylic acid（H2bpdc）,has been obtained through a hydrothermal technique（bpp = l,3-bis（4-pyridyl）propane）.Its single-crystal structure has been characterized by single-crystal X-ray diffraction,powder XRD,FT-IR,TGA and elemental analysis techniques.The single-crystal X-ray diffraction reveals that complex 1 consists of 1D infinite[Ag（bpp）（H2O）]n^（n＋）cationic chains,2D anionic layer constructed by bpdc anions and free water which provide charge compensation in the crystal structure.The 1D infinite[Ag（bpp）（H2O）]n^（n＋） cationic chains and 2D anionic layer are further stacked in-ABAB- fashion through intermolecular H-bonding to form a 3D sandwich-like framework.In addition,the luminescent property of complex 1 in the solid state at room temperature was investigated.

EffectofEr^(3+) and Nd^(3+)doping on the luminescent properties of BaMgAl_(10)O_(17):Euphosphor

BaMgAl_(10)O_(17):Eu blue phosphors were synthesized and the effect of dopingE^(3+) and Nd^(3+) ions in the phosphor on the luminescent properties was investigated. When thecontent of Er^(3+) and Nd^(3+) ions is small, the phosphor remains single phase and the luminescentintensity of Eu^(2+) increases effectively. When Er^(3+) is doped, the shape of the excitationspectrum of the phosphor in the UV (ultraviolet) region remains unchanged. As Nd^(3+) is doped inthe phosphor, the location and intensity of the two excitation peaks, and the emission intensityratio excited by corresponding UV change dramatically owing to the alternation of crystal fieldsplitting and level barycenter of 4f^6 5d configuration of Eu^(2+) ion.

Specific Recognition of Breast Cancer Cells In Vitro Using Near Infrared-Emitting Long-Persistence Luminescent Zn_3Ga_2Ge_2O_(10):Cr^(3+)Nanoprobes

In this paper, near-infrared emitting long-persistence luminescent Zn3Ga2Ge2O10:Cr3?(ZGG) nanoparticles with diameters of 30–100 nm and bright luminescence were prepared by a sol–gel synthesis method. After the surface amination, the nanoparticles were further bioconjugated with breast cancer-specific monoclonal antibody(anti-Ep CAM) to form ZGG-Ep CAM nanoprobes which can specifically target breast cancer cell lines(MCF7) in vitro. The results of in vitro images show that the luminescence signals from the cells treated with ZGG-Ep CAM nanoprobes are stronger than those from cells treated with ZGG-unconjugated antibody, indicating that the prepared ZGG-Ep CAM nanoprobes possessed excellent specific recognition capability. Furthermore, due to their long afterglow properties, the imaging could persist more than 1 h. Therefore, these nanoprobes could not only provide a high specificity detection method for cancer cells but also realize the long-time monitoring. Developed near-infrared emitting long-persistence luminescent nanoprobes will be expected to find new perspectives for cell therapy research and diagnosis applications.

Synthesis, Crystal Structure and Luminescent Properties of the Indium(Ⅲ) Complex Based on 2,6-Bis(1-phenylbenzimidazol-2-yl)pyridine

The complex [In（bpbp）Cl3]·H2O, where bpbp is 2,6-bis（1-phenylbenzimidazol- 2-yl）-pyridine （bpbp）, was synthesized and characterized by X-ray single-crystal structure analysis. For the complex： C31H21Cl3InN5·H2O, Mr = 702.71, monoclinic, space group, P21/n, a = 9.3918（10）, b = 21.024（2）, c = 14.5323（15）, β = 96.938（2）°, V = 2848.4（5）3, Z = 4, Dc = 1.639 g/cm3, λ = 0.71073, μ（MoKα） = 1.147 mm-1, F（000） = 1408, S = 1.00, R = 0.0430 and wR = 0.1438 for 4620 observed reflections with Ⅰ 〉 2σ（Ⅰ）. It is a neutral complex. The In（Ⅲ） ion adopts a distorted trigonal bipyramidal geometry coordinated by three nitrogen atoms of the ligand and three chlorine atoms. The complex emits blue luminescence with emission peaks at 430 nm in the solid state.

A New 2D Layered Barium Coordination Polymer [Ba(3-NPA)]_n: Synthesis, Crystal Structure, Thermal Stability and Luminescent Properties

A new two-dimensional （2D） barium（AA） coordination polymer [Ba（3-NPA）]n （1） has been obtained by the hydro/solvothermal reaction of the corresponding metal salt with 3-nitrophthalic acid （3-NPAH2）. Compound 1 was characterized by infrared spectrum, elemental analysis, powder X-ray diffraction （PXRD） and single-crystal X-ray diffraction analysis. Compound 1 crystallizes in triclinic, space group Pī with a = 4.9611（3）, b = 7.2599（4）, c = 12.9463（8） A, α = 89.0892（2）, β = 80.546（2）, γ = 73.211（2）°, V = 440.1（5） A3, Z = 2, C8H3BaNO6, Mr = 346.45, Dc = 2.614 g·cm^-3, μ = 4.526 mm^-1, S = 1.035, F（000） = 324, R = 0.0168 and wR = 0.0471 for 1712 observed reflections with I 〉 2σ（I）. （Aρ）max = 0.458, （Aρ）min = -0.565 e·A-3 and （A/σ）max = 0.001. In compound 1, each 3-NPA^2- ligand links six Ba（II） ions and each Ba（II） ion attaches to six 3-NPA^2- ligands to form an inorganic layer structure in the ab-plane. The phenyl groups of 3-NPA^2- ligands are grafted on the two sides of the inorganic layer, resulting in a two-dimensional （2D） layered structure. Furthermore, the thermal stability and luminescent properties of compound 1 have also been investigated in detail.