Intense Green Emission Research Articles

Power dependent photoacoustic and photoluminescence studies on a Ho3+/Yb3+ doped Y2O3 phosphor.

The Ho3+/Yb3+ doped Y2O3 phosphor samples were synthesized through a combustion method and then were annealed at 800 °C, 1000 °C, and 1200 °C. The cubic phase of the synthesized samples was confirmed by XRD analysis. The upconversion (UC) & photoacoustic (PA) spectroscopic studies were done on prepared samples and both spectra are compared. The samples have shown intense green upconversion emission at 551 nm due to the 5S2 → 5I8 transition of Ho3+ ion along with other bands. The maximum emission intensity is obtained for the sample annealed at 1000 °C for 2 hours. The authors have also measured the lifetime corresponding to 5S2 → 5I8 transition and found that lifetime values follow the trend of upconversion intensity. The maximum lifetime of 224 μs is observed for the sample annealed at 1000 °C. A photoacoustic cell & a pre-amplifier was fabricated and optimized for maximum sensitivity of the system. The PA signal was found to increase with increase of excitation power within the studied range, while UC emission was found to saturate after a certain pump power. The increase in PA signal is due to the increase in non-radiative transitions in the sample. The wavelength-dependent photoacoustic spectrum of sample has shown absorption bands around 445, 536, 649 and 945 (970) nm with maximum absorption at 945 (970) nm. This indicates its potential for photo-thermal therapy using infrared excitation.

A zeolitic imidazolate framework-90-based probe for fluorescent detection of mitochondrial hypochlorite in living cells and zebrafish.

An inorganic-organic hybrid probe MP-ZIF-90 was synthesized via a simple condensation reaction based on the free CHO groups of zeolitic imidazolate framework-90 (ZIF-90) and 4-methyl-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl)pyridinium bromide (MP). This probe exhibited intense green emission, which was selectively quenched by the addition of ClO- anions. The response of probe MP-ZIF-90 toward ClO- was rapid (within 20 s) and sensitive, with a limit of detection (LOD) of 0.612 μM. Importantly, the utilization of the probe in the fluorescence imaging of ClO- anions in the mitochondria of living cells and zebrafish was demonstrated.

MnCl3(H2O)3]- to [MnCl6]4-: The effect of inorganic polyhedron transformation on luminescence characteristics

Organic-inorganic hybrid halides (OIHs) have attracted widespread attention because of their exceptional optoelectronic properties. In particular, Mn2+-based hybrid halides show intense green or red emission, which benefit from distinct d-d optical transition in Mn2+. This work deals with the dual-emission in two novel hybrid single-crystals (N-AEP)[MnCl3(H2O)3]2·Cl (1) and [(N-AEP)2MnCl6]·2Cl (2) (N-AEP3+ = C6H18N33+). Luminescence properties studies indicate that the low-energy emission is assigned to the Mn2+-based octahedron, while the high-energy emission ascribes to the organic cation [N-AEP]3+. Inorganic polyhedron transformation ([MnCl3(H2O)3]- to [MnCl6]4-) increased the luminescent intensity, which benefited from the weaker nonradiative transition in [MnCl6]4- octahedron. Significantly, by finely adjusting the excitation wavelength, complex 2 showed tunable emission properties, realizing the transition from “warm” white light (0.40, 0.33) to “cold” white light (0.28, 0.28). This paper offers a new example on the effective design of dual-emission materials.

Dual excitable upconversion nanoparticle@polydopamine nanocomposite with intense red emission and efficient photothermal generation

Integration of strong upconversion emission with deep tissue penetration and stable photothermal generation is of great significance for imaging-guided photothermal therapy under infrared excitation. Herein, the NaYF4:Yb3+,Ho3+,Ce3+@NaGdF4:Yb3+,Nd3+@NaGdF4 core-shell-shell upconversion nanoparticles (UCNPs) with increasing Ce3+ doping concentration were firstly synthesized, in which the size manipulation, enhanced red to green emission intensity ratio (IR/IG), 980 and 808 nm dual-modal excitations, as well as improved total upconversion emission intensity can be achieved. After the coating of polydopamine (PDA) through dopamine spontaneous polymerization on the UCNPs surface under alkaline condition, the obtained UCNP@PDA nanocomposites show efficient photothermal effect under 808 nm excitation, while the thickness variation of PDA can be indicated by the upconversion spectra under 980 nm excitation. Interestingly, the photothermal effect of the UCNP@PDA nanocomposites with high IR/IG ratio is more stable with PDA thickness variation, which benefits from the structure design that allows PDA to simultaneously absorb the visible emission from inside UCNPs and the external 808 nm infrared light. Further in vitro cytotoxicity assay and photothermal therapy demonstrate that the UCNP@PDA nanocomposite has good biocompatibility and ability to kill tumor cells by photothermal effect under 808 nm excitation. This research may provide a nanoplatform for integrating deep bioimaging with highly stable photothermal therapy without the sacrifice of radiative transitions of rare earth ions.

Enhancement of up-conversion luminescence efficiency and temperature sensing properties in BaWO4: Ho3+/Yb3+ phosphor via Gd3+ incorporation

In this work, tungstate BaWO 4 phosphors doped Ho 3+ -Yb 3+ -Gd 3+ ions are successfully synthesized through solid-state reaction method. Under the excitation of a 980 nm laser, the up-conversion (UC) luminescence properties are investigated simultaneously. The blue (465 nm, 489 nm), green (541 nm) and red (665 nm) emission intensities of BaWO 4 : Ho 3+ /Yb 3+ /Gd 3+ samples are dramatically enhanced by 20.59, 9.83, 7.37, and 27.59 times more than those without Gd 3+ ions. The possible reason is discussed, which attributes to the energy transfer efficiency enhancement from Yb 3+ to Ho 3+ due to the lattice expansion induced by Gd 3+ ions. The temperature-sensing properties of BaWO 4 : Ho 3+ /Yb 3+ /Gd 3+ samples are also discussed based on the fluorescence intensity ratio (FIR) technology. The sensitivity of temperature measurement for BaWO 4 : Ho 3+ /Yb 3+ /Gd 3+ sample is higher than that of BaWO 4 : Ho 3+ /Yb 3+ . It proves that the codoped Gd 3+ ions can also increase the temperature sensitivity because the higher UC emission efficiency will lead to a high signal-to-noise ratio. The result provides an effective way to design UC luminescence materials with high temperature sensing properties.

Rare-Earth-Doped Barium Molybdate Up-Conversion Phosphor with Potential Application in Optical Temperature Sensing.

A BaMoO4:[Er3+]/[Yb3+] up-conversion (UC) phosphor was synthesized by co-precipitation and calcination of the precursor at 800 °C. The main peak (112) for the synthesized phosphor was strongly detected in the XRD pattern and had a tetragonal structure. The doping of rare-earth ions affected the crystal lattice by shifting the main peak, decreasing the lattice constant, and shifting the position of the Raman signal. The synthesized upconverted phosphor exhibited strong green signals at 530 and 553 nm and weak red signals at 657 nm when excited at 980 nm. The green light emission intensity of the UC phosphor increased as the pump power of the laser increased due to the two-photon effect. The synthesized upconverted phosphor was prepared as a pellet and flexible composite. Thermal quenching led to a decrease in luminescence intensity as the temperature increased, which means that the phosphor can be applied to optical temperature sensing.

Improvement in the dual-mode multicolor luminescence of the NaAlSiO4:Er3+, Yb3+ phosphors and the mechanistic investigations

Na0.90-yAlSiO4:0.1Er3+,yYb3+ (0 ≤ y ≤ 0.007) phosphors were prepared by the solid state reaction method and their dual mode multicolor luminescence properties were systematically investigated. The phosphors were crystallized into the carnegieite polymorph of NaAlSiO4 at 1300 °C. The synthesized phosphors were characterized by using powder XRD technique, FT-IR and UV-VIS-NIR diffuse reflectance spectra. Upon 380 nm excitation, the phosphors emitted visible and NIR downconversion emission, which follows the quantum cutting process. The upconversion emission spectra, irrespective of the laser excitation wavelength (980 nm, 808 nm, or 1550 nm), show characteristics sharp green, and red emissions, from 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, and 4F9/2 → 4I15/2 transitions of Er3+, respectively. Intense green (552 nm), red (664 nm) and NIR (809 nm) emissions were observed at 980, 808 and 1550 nm laser excitation, respectively. The dual mode emission of the Na0.90-yAlSiO4:0.1Er3+,yYb3+ (0 ≤ y ≤ 0.007) phosphors is enhanced upon Yb3+ co-doping. By analyzing the dependence of upconversion emission intensities on the laser excitation power, a possible upconversion emission mechanism is proposed.

Novel efficient SrMgY3(SiO4)3F:Ce3+,Tb3+ phosphor with tunable color and thermal stability through energy transfer

AbstractA novel apatite‐type SrMgY3(SiO4)3F was synthesized by a high‐temperature solid‐state reaction. The crystal structure was refined using powder X‐ray diffraction data. SrMgY3(SiO4)3F crystallizes in P63/m hexagonal space group with lattice parameters of a = b = 9.45270 Å, c = 6.77617 Å, and V = 524.357 Å3. The incorporation of the Ce3+ and Tb3+ ions into the matrix can generate bright blue and green lights under ultraviolet (UV) light excitation. The codoped Ce3+ and Tb3+ in SrMgY3(SiO4)3F can effectively improve green emission intensity and thermal stability through the energy transfer from the Ce3+ to Tb3+ ions. With the increase of Tb3+‐doping content, the luminescent color of phosphor changes from blue to cyan and finally to green. SrMgY3(SiO4)3F:0.06Ce3+,0.90Tb3+ phosphor exhibited intense green light emission with a quantum yield of 59.49% and good thermal stability, with an emission intensity at 150°C was 96% of that at 30°C. Finally, the prepared sample was coated on 365 nm UV chips to fabricate white light‐emitting diodes with a color rendering index of 82.6 and a correlated color temperature of 2912 K, demonstrating its potential for applications in display and lighting.

Tourism Development, Carbon Emission Intensity and Urban Green Economic Efficiency from the Perspective of Spatial Effects

In recent years, China has increasingly emphasized green development. Therefore, it is of theoretical and practical significance to study the green economic effect and carbon reduction effect of tourism development for the transformation of economic development. Using the superefficient EBM to measure the green economic efficiency of 280 cities from 2007–2019, we rely on the spatial Durbin model to explore the spatial spillover utility and nonlinear characteristic relationship of tourism development on green economic efficiency and carbon emission intensity and test the mediating effect of carbon emission intensity. The findings are as follows: (1) Under the exogenous shock test of the “low-carbon city” pilot policy, the spatial spillover effect of tourism development on urban green economic efficiency and carbon emission intensity is robust to spatial heterogeneity. (2) The spatial spillover effects of tourism development on the green economic efficiency and carbon emission intensity of cities show a nonlinear characteristic relationship of “U” and “M” shapes. After tourism development reaches a certain high level, the green economy effect and carbon emission reduction effect are significantly increased. (3) Carbon emission intensity has a significant mediating effect on the impact of tourism development on urban green economic efficiency.

Multifunctional Platform Based on a Copper(I) Complex and NaYF4:Tm3+,Yb3+ Upconverting Nanoparticles Immobilized into a Polystyrene Matrix: Downshifting and Upconversion Oxygen Sensing.

This work presents an innovative approach to obtain a multifunctional hybrid material operating via combined anti-Stokes (upconversion) and Stokes (downshifting) emissions for oxygen gas sensing and related functionalities. The material is based on a Cu(I) complex exhibiting thermally activated delayed fluorescence emission (TADF) and infrared-to-visible upconverting Tm3+/Yb3+-doped NaYF4 nanoparticles supported in a polystyrene (PS) matrix. Excitation of the hybrid material at 980 nm leads to efficient transfer of Tm3+ emission in the ultraviolet/blue region to the Cu(I) complex and consequently intense green emission (560 nm) of the latter. Additionally, the green emission of the complex can also be directly generated with excitation at 360 nm. Independently of the excitation wavelength, the emission intensity is efficiently suppressed by the presence of molecular oxygen and the quenching rate is properly characterized by the Stern-Volmer plots. The results indicate that the biocompatible hybrid material can be applied as an efficient O2 sensor operating via near-infrared or ultraviolet excitation, unlike most optical oxygen sensors currently available which only work in downshifting mode.

Optical Properties and Concentration Quenching Mechanism of Er3+ Heavy Doped Gd2(MoO4)3 Phosphor for Green Light-Emitting Diode.

Upconversion materials capable of converting low-energy excitation photons into high-energy emission photons have attracted considerable interest in recent years. However, the low upconversion luminescence seriously hinders the application of upconversion phosphors. Heavy lanthanide doping without concentration quenching represents a direct and effective method to enhance the emission intensity. In this study, Er3+ heavy doped Gd2(MoO4)3 phosphor with a monoclinic phase was prepared by a sol–gel process. Under excitation at 976 nm, Gd2(MoO4)3:Er3+ phosphor emitted remarkably intense green emission, and Er3+ concentration up to 20 mol% did not cause concentration quenching. Here, we discuss the upconversion mechanism and concentration quenching. When the Er3+ concentration was in the range of 30–60 mol%, the concentration quenching was governed by the electric dipole–dipole interaction, and when the concentration was greater than 60 mol%, the concentration quenching was controlled by the exchange interactions. The result provides a schematic basis for identifying a phosphor host with heavy lanthanide doping.

Benzothiadiazole‐Based Green Hybridized Local and Charge‐Transfer (HLCT) Fluorophores as Solution‐Processed Non‐Doped Emitters for Simple Structured Electroluminescent Devices

AbstractHerein, two new solution‐processable HLCT fluorophores (CBzF and CBzFC) based on benzothiadiazole (Bz) derivatives were designed and synthesized (HLCT=hybridized local and charge transfer). Their optical and photophysical properties were experimentally and theoretically studied and verified by the solvatochromic effect and density functional theory calculations. The two molecules demonstrate high solubility, HLCT features, and an intense green fluorescence with solid‐state photoluminescence quantum yields of 63–72 %. Both fluorophores are effectively applied as non‐doped emitters for solution‐processed double‐layered OLEDs, which produce intense green emission colors with low turn‐on voltages (3.0–3.2 V). Specifically, the CBzFC‐based solution‐processed device achieves a high maximum luminescence (24400 cd m−2), high maximum efficiencies (EQEmax=5.59 %, CEmax=12.24 cd A−1, and PEmax=10.54 lm W−1), and decent efficiency low‐off.

Polymer‐derived β‐SiAlON:Eu2+ phosphors

AbstractA series of β‐SiAlON:Eu2+ phosphors were synthesized from single‐source precursors, perhydropolysilazane chemically modified with Al(OCH(CH3)2)3, AlCl3, and EuCl2. The single‐source precursors were converted to β‐SiAlON:Eu2+ phosphors by pyrolysis under flowing N2 or NH3 at 1000°C, followed by heat treatment at 1800°C under an N2 gas pressure at 980 kPa. By varying the molar ratio of the chemical modifiers, β‐SiAlON:Eu2+ with the compositions close to the theoretical ones expressed as Si6−zAlzOz−2yN8−z+2y:yEu2+ were synthesized, where the z values and Eu2+ contents were controlled in the ranges of .44–.78 and .35–1.48 mol%, respectively. The polymer‐derived β‐SiAlON:Eu2+ phosphors exhibited green emission under excitation at 460 nm attributed to the 4f7–4f6(7f3)5d1 transition of dopant Eu2+. High‐angle annular dark‐field‐scanning transmission microscopy analysis confirmed that the doped‐Eu2+ existed interstitially within the channels along the c axis of host β‐SiAlON. Compared with the conventional powder metallurgy route, the polymer‐derived ceramic route in this study offers some advantages in the grain growth of host β‐SiAlON and photoluminescence properties in terms of green emission intensity under excitation at 460 nm, and the highest intensity was achieved for the polymer‐derived β‐SiAlON:Eu2+ with z = .64 and .37 mol% Eu2+.

The effect of ion radius on luminescence for alkali ions doping in Y2O3: Yb3+/Ho3+ thin film

In this paper, alkali ion (Li+ Na+ K+ and Rb+)-doped Y2O3:Yb3+/Ho3+ up conversion films were prepared using the sol–gel method. The structures of the films were studied by using X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. A series of high-quality thin films with good crystallization were prepared. For all samples, two emission bands were observed: green emission at 539 (550) nm and red emission at 664 nm, which can be attributed to 5F4 (5S2)→5I7 and 5F5→5I8, respectively. The green emission is dominant, and the red emission is extremely weak. The effect of each alkali-ion dopant on the emission and color adjustment of samples was investigated. The green emission intensity is increased by a factor of 6.33 (Li), 2.03 (Na), 4.82 (K) and 1.92 (Rb) with increasing alkali-ion doping concentration, and red emission is increased by a factor of 7.80 (Li), 1.92 (Na), 4.78 (K) and 1.90 (Rb). The extreme value appears earlier with increasing ion radius. Li+ doping boosts luminescence in three ways, and the other alkali ions affect the light emission in two ways. Li+ doping and K+ doping can be used to adjust the color coordinates towards the 539 nm and 550 nm directions, respectively. Na+ and Rb+ doping can enhance emission with a stable color. This means that each alkali ion is a suitable choice as a color-regulating ion and can play a role in the regulation of luminescence.

A highly stable 2D Zn-based coordination polymer exhibiting efficiently luminescent sensing towards sulfasalazine

A robust 3D supramolecular Zn(II)-based coordination polymer having formula [Zn(H2L)(bpyp)·H2O] (1) (H3L = benzene-1,3,5-tricarboxylic acid and bpyp = 2,5-bis(pyrid-4-yl)pyridine) has been hydrothermally synthesized and characterized. The single crystal X-ray analysis revealed that the polymer 1 possesses a paddle wheel-shaped [Zn2(COO)4] subunit extended by H3L and bpyp linkers, showing high environmental stability, good dispersion and intense green emission in aqueous system. 1 used as a photoluminescent sensor exhibits rapid and efficient fluorescent response towards sulfasalazine (SLA) with strong quenching constants and low detection limit of 1.65 ppm. Additionally, 1 exhibits strong anti-interference and outstanding regeneration capabilities in its sensitive and selective recognition of SLA, which enhances its potential for use as a sensing material. Furthermore, the sensing mechanism study shows that photo-induced charge transfer and competitive absorption are responsible for quenching of emission in 1.

One-Pot Synthesis of Pyreno[2,1-b]furan Molecules with Two-Photon Absorption Properties.

The development of large π-conjugated polycyclic heteroaromatic materials is of immense interest, both in the academic as well as the industrial community. Herein, we present the efficient one-pot synthesis of novel pyreno[2,1-b]furan molecules from a newly designed intermediate, which display intense green emission (505-516 nm) in solution and a large red shift emission (625-640 nm) in the solid state, because of strong π-π stacking. More interestingly, the compounds exhibit novel two-photon absorption (TPA) properties, and the TPA cross-section (δ) value was increased to 533 GM by regulating the electronic effects of the substituents of the pyreno[2,1-b]furan molecules. This study not only offers a facile strategy for constructing new pyrene-fused luminescence materials with two-photon absorption properties but also provides a new chemical intermediate that opens up a new pathway to advanced materials.

Intense green photoluminescence and upconversion-based intrinsic optical bistability in Ho3+/Yb3+ codoped CaSc2O4 and upconversion in Ho3+/Yb3+ codoped CaY2O4 phosphors

The present study details the downshifting, frequency upconversion and intrinsic optical bistability in CaSc2O4:Ho3+/Yb3+ and upconversion in CaY2O4:Ho3+/Yb3+ phosphors synthesized by a complex-based precursor solution method. The X-ray powder diffraction confirms the formation of highly crystalline phosphors with pure orthorhombic phase. Fourier transform infrared studies of synthesized phosphors show vibrational bands due to the presence of Ca–O, Sc–O and Y–O groups. The diffuse reflectance spectra show a number of bands in the UV–vis–NIR regions due to presence of Ho3+ and Yb3+ ions. The values of optical band gap (Eg) are found to be 5.69 eV and 5.58 eV for the Ho3+/Yb3+ codoped CaSc2O4 and CaY2O4 phosphors, respectively. The Ho3+/Yb3+ codoped CaSc2O4 phosphors display intense green downshifting emission upon 454 nm excitations. The lifetime of green luminescence of CaSc2O4:Ho3+/Yb3+ phosphors with varied Yb3+ concentrations have also been measured. The decay curves show a non-exponential nature fitted to the Inokuti-Hirayama model and the energy transfer microscopic parameters have been also calculated. The Ho3+/Yb3+ co-doped CaSc2O4 and CaY2O4 phosphors display intense green alongwith weak blue, red, and near-infrared upconversion (UC) emissions upon 980 nm excitations. The spectral color purity (Sgr) of CaSc2O4:Ho3+(1%)/Yb3+(5%) phosphor is calculated to be 0.78. Importantly, the variation of pump power generates intrinsic optical bistability (IOB) in the CaSc2O4:Ho3+(1%)/Yb3+(5%) phosphor for the green emission, which is not observed in the CaY2O4:Ho3+(1%)/Yb3+(5%) phosphor. Therefore, the Ho3+/Yb3+ co-doped CaSc2O4 phosphor could potentially be used in UC-based devices, optical memory devices, optical gates, optical transistors and switching devices for optical communications.

A neoteric approach to achieve BaF2:Yb3+, Er3+ one-dimensional nanostructures with color-tuned up-conversion luminescence

One-dimensional (1D) nanostructures have received considerable attention owing to their peculiar traits and extensive applications. Alkaline-earth metal fluorides are favorable substrates for rare earth ions luminescence. Most of the rare-earth-doped alkaline-earth metal fluorides nanomaterials obtained by current methods are in the form of nanoparticles without one-dimensional nanostructures. Therefore, the convenient and quick preparation of rare-earth-doped alkaline-earth metal fluorides 1D nanostructures has become an important topic of study. In this work, BaF2:Yb3+, Er3+ up-conversion luminescence (UCL) 1D nanostructures, as a case study, have been designed and constructed via recently proposed mono-axis electrospinning united with dual-crucible fluorating technology. Controllable fabrications of BaF2:Yb3+, Er3+ nanofibers, nanobelts and hollow nanofibers 1D nanostructures are successfully and facilely realized via simply regulating the compositions and ratios of the electrospinning solutions by applying the above technique. The effects of morphology, calcination temperature and molar ratios of Yb3+ to Er3+ on the UCL characteristics of the samples are systematically investigated, and color-tuned up-conversion luminescence is achieved. It is found that as-obtained pure cubic-phase BaF2:Yb3+, Er3+ 1D nanostructures display excellent UCL properties under the 980-nm laser excitation, and the intensity of green emission (2H11/2 → 4I15/2 and 4S3/2 → 4I15/2) is greater than that of red emission (4F9/2 → 4I15/2), leading to superior green fluorescence. Further, the BaF2:Yb3+, Er3+ nanofibers have the strongest fluorescence intensity of the three kinds of morphological samples, realizing modulation of luminous intensity via regulation of morphologies. The detailed luminescent mechanisms of the samples are advanced. The fabrication techniques are established and the formative mechanisms of the 1D nanostructures are detailedly elaborated. More notably, the proposed design concept and preparation technique can be extended to manufacture other metallic fluorides 1D nanomaterials.

Green Up-Conversion Luminescence in Yb/Er Co-Doped AlN Thin Film by RF Magnetron Sputtering

In this research study, aluminum Nitride (AlN) thin film co-doped with erbium and ytterbium has been deposited on Si (100) substrate by RF magnetron Sputtering. After deposition, the film was annealed at 1100 °C in ambient conditions. It’s structural properties were investigated X-ray diffraction (XRD). Thin films morphology is studied using SEM, and EDX provides the chemical composition information. The photoluminescence property of deposited film was investigated by FS5 spectrofluorometer. XRD result revealed that the film has grown along the c-axis oriented in hexagonal wurtzite structure. SEM Result shows that the average size of the particle is 100 nm. The up-conversion luminescence showed intense green and red emission peaks at 530 nm, 552 nm, and 665 nm due to the transition of Er (2H11/2 → 4I15/2, 4S3/2 → 4I15/2, and 4F9/2 → 4I15/2) with excitation of 984 nm. The excitation wavelength with 483 nm photons produces visible luminescence in the green and red region with 557 and 660 nm due to Erbium.

Dual luminescence optimization of Ho3+/Yb3+/Eu3+-doped Gd2O3 phosphor prepared by spray pyrolysis for anti-counterfeiting application

Ho3+/Yb3+/Eu3+-doped Gd2O3 spherical particles with upconversion (UC) and down-conversion (DC) emission were synthesized by spray pyrolysis. The resulting phosphor showed intense DC red and UC green emissions. The Eu3+, Ho3+ and Yb3+ contents were optimized to simultaneously achieve the highest UC and DC emission. Resultantly, the optimal Eu3+, Ho3+ and Yb3+ doping concentrations were found as 0.2%, 3.0% and 0.2%, respectively. The green UC emission resulted from a typical two-photon process, and the UC and DC emission intensity showed a linear relationship with crystallite size. The microstructure of Gd2O3:Ho3+/Yb3+/Eu3+ was controlled by introducing organic additives into the spray solution. The use of organic additives made it possible to improve crystallinity having a dense morphology, which led to largely enhance the DC and UC intensity. The prepared Gd2O3:Ho3+/Yb3+/Eu3+ spherical particles showed excellent dual luminescence suitable as anti-counterfeiting security materials.