Luminescence Properties Of Y2O3 Research Articles

Structural and luminescence properties of Y2O3:Ho3+ phosphor: Potential applications in plant cultivation LEDs and thermoluminescent dosimetry

Current research on Y2O3:Ho3+ phosphors highlight their promising luminescence properties, but often lacks an environmentally friendly synthesis method and comprehensive analysis of their applications. In this study, we address these gaps by successfully synthesizing Y2O3:Ho3+ phosphors using a green synthesis route with varying concentrations of Ho3+. Our work provides detailed characterization of their photoluminescence (PL) and thermoluminescent (TL) properties. The PL excitation (PLE) spectra reveal a distinct peak at 439 nm, attributed to the 5I8→(5K5; 5G5) transition of Ho3+ions. Upon excitation at 439 nm, the emission spectra show a sharp emission peak around 660 nm from the 5F5→5I8 transition, with the 0.1 mol% Ho3+ phosphors exhibiting particularly strong red emission, indicating their suitability for indoor plant cultivation under LED lighting. Additionally, TL properties were evaluated after gamma-ray exposure, with the highest emission intensity at 0.1 mol% Ho3+ concentration. TL glow curves were analyzed for various radiation doses using the Computerized Glow Curve Deconvolution (CGCD) method, and TL trapping parameters were determined through Chen's peak shape and the Initial Rise methods. This work demonstrates significant potential for using these phosphors to enhance indoor plant growth and for applications in thermoluminescent dosimetry (TLD).

The role of thickness on the structural and luminescence properties of Y2O3:Ho3+, Yb3+ upconversion films

The structural, surface, and upconversion (UC) luminescence properties of Y2O3:Ho3+,Yb3+ films grown by pulsed laser deposition, for different numbers of laser pulses, were studied. The crystallinity, surface, and UC luminescence properties of the thin films were found to be highly dependent on the number of laser pulses. The X-ray powder diffraction analysis revealed that Y2O3:Ho3+,Yb3+ films were formed in a cubic structure phase with an Ia 3¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\overline{3 }$$\\end{document} space group. The thicknesses of the films were estimated by using cross-sectional scanning electron microscopy, depth profiles using X-ray photoelectron spectroscopy (XPS), and the Swanepoel method. The high-resolution XPS was used to determine the chemical composition and oxidation states of the prepared films. The UC emissions were observed at 538, 550, 666, and 756 nm, assigned to the 5F4 → 5I8, 5S2 → 5I8, 5F5 → 5I8, and 5S2 → 5I7 transitions of the Ho3+ ions. The power dependence measurements confirmed the involvement of a two-photon process in the UC process. The color purity estimated from the Commission International de I’Eclairage coordinates confirmed strong green UC emission. The results suggested that the Y2O3:Ho3+,Yb3+ UC transparent films are good candidates for various applications, including solar cell applications.

A Comparative Study on Luminescence Properties of Y2O3: Pr3+ Nanocrystals Prepared by Different Synthesis Methods.

Pr3+-doped Y2O3 nanocrystals (NCs) have been obtained via five wet-chemistry synthesis methods which were optimized in order to achieve superior optical properties. To this end, a systematic study on the influence of different reaction parameters was performed for each procedure. Specifically, precursor concentration, reaction temperature, calcination temperature, and time, among others, were analyzed. The synthesized Y2O3: Pr3+ NCs were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), and reflectance and Raman spectroscopy. In addition, the optical properties of such NCs were investigated by excitation, emission, and luminescence decay measurements. Concretely, emission from the 1D2 level was detected in all samples, while emission from 3PJ was absent. Finally, the effect of the synthesis methods and the reaction conditions on the luminescence decay has been discussed, and a comparative study of the different methods using the fluorescence lifetime of so-obtained Y2O3: Pr3+ NCs as a figure of merit has been carried out.

Structural and luminescence properties of Y2O3:Eu3+red phosphor by incorporation of Ga3+ and Bi3+ions

The cationic substitution of Y3+simultaneously with Bi3+/Ga3+ ions on the crystal structure of the Y2O3:Eu3+ phosphor and its effect on the structure, the luminescence and thermoluminescence properties was investigated. Four samples were prepared by using a sol-gel combustion method. The substitution of Bi3+/Ga3+ ions modified the Y2O3:Eu3+ phosphor structure, which showed a transition phase structure. In addition, the presence of Bi3+/Ga3+ ions simultaneously in the Y2O3:Eu3+ phosphor structure affected the optical properties. The excitation at 305 nm gave the characteristic emission peaks of the Eu3+ ions with a remarkable increase in the intensity of the peak at 628 nm compare to the same peak that was excited using the Bi3+excitation at 330 nm. The Judd-Ofelt theory was used to estimate the photometric parameters. The TL glow curves of UV-irradiated samples showed a low temperature peak at about 402 K and a high temperature peak at 543 K. A significantly change in the TL intensities for the different dopants in the Y2O3 was observed. The TL kinetics parameters were calculated by a deconvolution computer fitting program using the general order kinetic equation. Different dopants in the Y2O3 was observed with defect levels ranging from 0.8 to 1.8 eV.

Structural and luminescence properties of Y2O3:Bi2.0 mol%,Yb10.0 mol% thin films prepared using the pulsed laser deposition and spin coating technique

Y2O3:Bi2.0 mol%,Yb10.0 mol% thin films were successfully prepared using the pulsed laser deposition (PLD) and spin coating technique. The X-ray diffraction patterns revealed that the spin coating thin films crystallised with a single phase cubic structure, while the films produced using PLD had an additional monoclinic phase. Due to the laser ablation process the thin films, prepared using PLD, had micron size particulates present on the surface. The thin films prepared using spin coating were smooth at first but increasing the molarity of the precursor solution and the number of coatings applied to the substrate, cracking and peeling of the films occurred due to poor adhesion. The emission, both in the visible and infrared where consistent to that of the starting Y2O3:Bi2.0 mol%,Yb10.0 mol% phosphor powder.

Effects of electron beam current on microstructure and luminescent properties of Y2O3:Eu3+ thin film grown on quartz fabric by electron beam evaporation

Thin films of yttrium oxide phosphor doped with trivalent europium ion (Y2O3:Eu3+) are grown on a quartz fabric substrate by using electron beam evaporation with different electron beam currents from 80 to 170 mA. The dependence of morphological structure, crystal structure, luminescent properties and chromaticity coordinates of Y2O3:Eu3+ thin films on the electron beam current is thoroughly analyzed. The experimental results show that the thickness of the films is significantly increased from 0.69 to 1.68 µm when the deposition current is increased from 110 to 170 mA. Improvements in the surface morphological components, such as spherical-shaped particles and a more dense topography, can be found when the films are deposited with a current of 140 mA. The predominant orientation of the Y2O3:Eu3+ thin films transforms from the (400) to (222) crystal face when the current is increased from 110 to 140–170 mA. The maximum crystallinity of the films occurs when the deposition current is used at 140 mA. The luminescent spectra results indicate that the improved morphology, inceased film thickness and enhanced crystallinity can contribute to the better luminescent properties of the Y2O3:Eu3+ thin films. The highest emission brightness is obtained when the Y2O3:Eu3+ thin films are prepared with a deposition current of 140 mA, and the luminescent intensity is increased by 6317% when the deposition current is increased from 80 to 140 mA.

Synthesis of equal-sized Y2O3:Bi,Eu mono-spheres and their color-tunable photoluminescence and thermal quenching properties

On the basis of the synthesized equal-sized mono-spheres (~ 180 nm), the luminescence properties of Y2O3:0.2 mol%Bi,2xmol%Eu (x = 0.1–7) phosphors were investigated in detail. The PL spectra of Y2O3:Bi,Eu mono-spheres displays both the bluish green/blue emission of Bi3+ at 501/410 nm (3P1-1S0, Bi3+ in C2 or S6 sites) and the red emission of Eu3+ at 612 nm (5D0–7F2) upon 330/375 nm excitation. Increasing the doping concentration of Eu3+ ions in the phosphor mono-spheres significantly enhances Eu3+ emission (5D0–7F2) and reduces Bi3+ emission (3P1-1S0) due to the effective energy transfer from Bi3+ to Eu3+ ions. At the optimal Eu3+ concentration of 3 mol%, the Y2O3:Bi,Eu mono-spheres show an intense red emission and a high external quantum efficiency of 42.8%. The energy transfer (ET) process from Bi3+ to Eu3+ ions is determined to be a resonant type via dipole-quadrupole interaction with an ET efficiency of 86.3%. By varying the Eu3+ concentration, the luminescence color can be tuned from bluish green to nearly white and eventually to orange red under 330 nm excitation (Bi3+ in C2 sites), and also can be tuned from blue to pink and then to orange red under 375 nm excitation (Bi3+ in S6 sites). Temperature-dependent luminescence spectra demonstrated the good thermal stability of the obtained phosphor mono-spheres.

Morphology-tailored synthesis and luminescent properties of Y2O3:Eu3+ phosphors

The size and shape of functional micro/nanomaterials have crucial influence on their physical and chemical properties. The monoclinic Y4O(OH)9NO3 with nanosheets, submicrospheres, and microrods have been successfully prepared by a non-aqueous solvothermal method. The precursors Y4O(OH)9NO3 decompose into cubic Y2O3:Eu3+ phosphors after sintering at 800 °C for 2 h. The morphologies and sizes of Y2O3:Eu3+ particles can be easily controlled by changing the growth rates of various crystallographic facets during solvothermal process. With the increment of the rare-earth nitrates concentration, the morphologies transform from 2D nanosheets to sub-microspheres, and eventually to microrods. The bright red emission, owing to Eu3+ f-orbital transitions, can be easily observed under ultraviolet excitation. Furthermore, the dependence of Y2O3:Eu3+ luminescence performances on different morphologies are discussed in the present work.

CO2 laser annealing for improved luminescent properties of Y2O3:Eu3+ thin film grown on quartz fabric by using EBE

Thin films of yttrium oxide phosphor doped with trivalent europium ion (Y2O3:Eu3+) are grown on a quartz fabric substrate by using electron beam evaporation (EBE) and subsequently annealed by a pulsed CO2 laser with different lengths of pixel time and resolutions. Energy distribution of the laser beam on the thin films is analyzed, and the dependence of surface morphology, crystal structure and luminescent properties of the resultant fabrics on the laser annealing parameters is also studied. The experimental results demonstrate that the microstructure and luminescent properties of the Y2O3:Eu3+ thin films are strongly affected by the CO2 laser annealing, and the increased emission brightness can be realized in the thin films because of the complete melting film with relatively integral topography and the improved crystallinity by controlling the CO2 laser parameters. The highest luminescence is obtained when the Y2O3:Eu3+ thin films are annealed with a resolution of 35 dpi and a pixel time for 120 μs, and the luminescent intensity of the films is increased by 253.27% in comparison to the as-deposited films.

Luminescence properties of Y2O3:Bi3+, Yb3+ co-doped phosphor for application in solar cells

Bismuth (Bi3+) and ytterbium (Yb3+) co-doped yttrium oxide (Y2O3) phosphor powder was successfully synthesised using the co-precipitation technique. The X-ray diffraction (XRD) patterns confirmed that a single phase cubic structure with a Ia-3 space group was formed. The visible emission confirmed the two symmetry sites, C2 and S6, found in the Y2O3 host material and revealed that Bi3+ ions preferred the S6 site as seen the stronger emission intensity. The near-infrared (NIR) emission of Yb3+ increased significantly by the presence of the Bi3+ ions when compared to the singly doped Y2O3:Yb3+ phosphor with the same Yb3+ concentration. An increase in the NIR emission intensity was also observed by simply increasing the Yb3+ concentration in the Y2O3:Bi3+, Yb3+ phosphor material where the intensity increased up to x = 5.0mol% of Yb3+ before decreasing due to concentration quenching.

Effects of Eu content on the luminescent properties of Y2O3:Eu3+ aerogels and Y(OH)3/Y2O3:Eu3+@SiO2 glassy aerogels

Abstract This article describes the morphological, structural, and luminescent properties of Y2O3:Eu3+ aerogels and Y(OH)3/Y2O3:Eu3+@SiO2 glassy aerogels synthesized by the sol-gel method with Eu concentrations from 2.5 mol% to 30 mol%. XRD measurements indicated that both the aerogels and glassy aerogels had a monoclinic phase, but the crystallinity in the glassy aerogels was lower due to the presence of SiO2. SEM images reveal that a three-dimensional porous network was formed in the aerogels due to the interconnection of coalesced Y2O3:Eu3+ nanoparticles. The 3D porous network was also observed in the glassy aerogels, coated with a silica shell. In both the aerogels and glassy aerogels, the size of the agglomerates decreased as the europium concentration increased. This, in turn, increased the average size of the macropores that formed their 3D network. Furthermore, the luminescent properties of the aerogels and glassy aerogels were studied under UV excitation, and it was observed that their red emission intensity increased continuously as the Eu3+ concentration increased. The luminescence of the aerogels was on average 50% higher than that of the glassy aerogels. Hence, our results indicate that porous and luminescent aerogels with and without silica are adequate for applications in sensing and catalysis.

Zinc Phosphate Glasses Doped Yttrium-Europium Oxide, a Luminescence Study

Zinc phosphate glasses doped with yttrium-europium oxide, were obtained by melting at 1100 °C; suitable precursors of these glasses quantities was grinded mechanically and dried at 400 °C for 2hrs, then the temperature was raised to 800 °C for 2hrs again, finally the temperature was raised at 1100 °C for 3hrs until a liquid is achieved, this liquid is emptied in a copper block to produce a thermal shock and observe the formation of a glass; a final heat treatment at 300°C for 12hrs is practiced. Luminescent studies were conducted in these glasses, it is observable, that when excited with λexc = 396nm are present the 5D0 to 7F1, 7F2, 7F3 y 7F4 transitions in 590, 616, 650, and 697 nm; the main emission is achieved at 616 nm and a high red light emission is observable at naked eye, due to the presence of europium ions. Absorption spectra, transmission and reflectance are obtained; these glasses are transparent in the region of 400 nm to 1100 nm UV; XRD indicates that samples are amorphous; the emission spectra of these glasses were doped with different amounts of yttrium-europium oxide; they depend on the amount of dopant. The luminescent properties of Y2O3:Eu3+ powders have been studied, luminescent Y2O3:Eu3+ polycrystalline powders were synthesized by a simple evaporation method. The photoluminescence and cathodoluminescence emission spectra these samples show, luminescence peaks associated with transitions within the electronic energy levels of Eu3+ ions. The dominant peak is at 612nm corresponding to the 5D0 to 7F2 transition and present 5D0 to 7F1, 7F2, 7F3 y 7F4 transitions in 590, 616, 650, and 697 nm, when excited with λexc = 260 nm and λexc= 396at room temperature. The intensity luminescence Y2O3:Eu3+ powders with different dopant concentrations, Eu3+ ion dependent percentage, finding the optimal concentration is 17 mol%. XRD of powders Y2O3:Eu3+ show these correspond to space group: Ia-3(206), with Cell: 10.6039 10.6039 10.6039 90.000 90.000 90.000, Volume: 1192.328 and whit Crystal System: Cubic (No: 01-075-3096); these powders were evaporated at 200 °C and then calcined for two hours at 1100°C. EDS analysis shows that the corresponding Y2O3:Eu3+ powders, showing that the achieved yttrium is stoichiometric according to general Y2O3 formula. According to the results of the photoluminescence of these powders Y2O3: Eu3+, to excite λexc = 396nm have the energy required for luminescence is less and therefore can obtain low-cost LEDs for red light; so it can be considered that this type of compound is a good candidate to have red light and its preparation is simple and inexpensive.

The effect of different annealing temperatures on the structure and luminescence properties of Y2O3:Bi3+ thin films fabricated by spin coating

This paper reports on the structural, morphology and optical properties of Y2−xO3:Bix=0.005 micro-and nanophosphors synthesized via the spin coating method. The influence of different annealing temperatures (900–1200°C) on the morphology, crystal structure and the photoluminescence (PL) properties of the synthesized films were studied in detail. The crystal structure of the films was investigated with X-ray diffraction. The presence of the three major diffraction peaks with Miller indexes (211), (222) and (400) indicated that the Y2−xO3:Bix=0.005 thin films were well-crystallized at 900°C, 1000°C, 1100°C and 1200°C. Additionally, extra diffraction peaks were observed for the sample that was annealed at 1200°C. Those extra peaks were due to the formation of the Y2Si2O7 phase owing to the annealing induced changes in the crystal structure and chemical composition of the Y2−xO3:Bix=0.005 thin film. This may also be attributed to inter diffusion of atomic species between the Si substrate and the Y2−xO3:Bix=0.005 thin film at the high annealing temperature. Due to structure-sensitive properties of the Bi3+ ions, a blue shift of the centre PL emission band from 495nm to 410nm was clearly observed and explained in detail. The time-of-flight secondary ion mass spectroscopy results show the Si diffusion from the Si substrate, whereas, the scanning electron microscopy and the atomic force microscopy were used for the morphology analysis.

Effect of Li+ and Zn2+ co-doping on PL properties of Y2O3:Eu3+ phosphor

In this paper we have reported the effect of co-doped on the luminescence properties of Y2O3:Eu3+ phosphors. The Y2O3:Eu3+ phosphors prepared by different methods such as combustion synthesis, precipitation methods, Pechini sol–gel method. XRD, SEM and FTIR analysis were carried out for the confirmation of phase purity, surface morphology and MO vibration in host lattice. Here we focused on the more desired route of synthesis of Y2O3:Eu3+ phosphor for high lumen output with low cost synthesis route. Detailed study has been presented on the emission properties of Y2O3:Eu3+ (Eu=1m%) due to various concentration of Li+ and Zn2+ by urea combustion method, precipitation method and Pechini sol–gel method. In this investigation, we found that PL intensity strictly depends on the method of preparation and concentration of co-dopant Li/Zn, in sample Y2O3:Eu3+ (Eu=1m%), and intensity of red emission peak enhances by, accountable factor by adding Li+ and Zn2+ in Y2O3:Eu3+. Thus the prepared phosphor is a promising red phosphor used in lamp industries.

Luminescence properties of Y2O3:Eu3+ nanocrystals prepared by the ultrasonic chemistry method.

Y2O3:Eu3+ nanocrystals were prepared by ultrasonic chemistry and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The resulting nanocrystals were found to be nanoparticles with size distribution in the range of 50-80 nm. The phase of all the samples was cubic. The luminescence properties of the samples were systematically studied and show significant change with concentration of surfactant and annealing temperature. The results show that the intensity of the excitation and emission spectra of Y2O3:Eu3+ nanocrytals increases gradually with increasing P123 concentration and annealing temperature. The fluorescence lifetime of 5D0 level Eu3+ decreases with increasing P123 concentration and increases with annealing temperature. The photoluminescence stability of Y2O3:Eu3+ nanocrytals becomes worse with increasing P123 concentration and annealing temperature.

1D structure of Y2O3:Eu nanorods: controllable synthesis, growth mechanisms and luminescence properties.

Y2O3O:Eu nanorods were successfully synthesized by a facile and effective hydrothermal method in the presence of P123 (EO106PO70EO106) as the surfactant followed by a subsequent heat treatment process. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images indicate that the as-prepared samples consist of nanorods with diameters ranging from 80 nm to 100 nm and grow along the (100) direction. The growth mechanism of the as-obtained Y2O3:Eu nanorods was proposed on the basis of pH-dependent experiments. It is found that the pH is a crucial factor in determining the phase, morphology and luminescence properties of Y2O3:Eu nanorods. The luminescent spectra of Y2O3:Eu nanorods show the strong characteristic dominant emission of the Eu3+ ions at 613 nm.

Microstructure and photoluminescent properties of Y2O3:Eu3+ phosphors synthesised by precipitation and combustion methods

Y2O3:Eu3+ phosphors were prepared by NH4HCO3 based precipitation method and C2H5NO2–nitrate solution combustion synthesis method respectively. The phosphors were systematically investigated by field emission scanning electron microscope (SEM), X-ray diffractometer (XRD), scanning electron microscope (XPS) and fluorescence spectrometer. Luminescent properties of Y2O3:Eu3+ phosphors synthesised by two different methods were also compared. The results show that Y2O3:Eu3+ phosphor prepared by precipitation technique is spherical with nanometre particle size from 55 to 60 nm, whereas the one synthesised by combustion technique exhibits extensive sheet porosity structure. X-ray diffraction spectra indicate that both of the samples have pure cubic phases and the crystallinity of phosphor synthesised by combustion technique is improved. The main emission peaks of Y2O3:Eu3+ phosphors at 613 nm are due to the 5D0–7F2 transition of Eu3+ ions, and phosphor obtained by precipitation method shows higher emission intensity. The results reveal that Y2O3:Eu3+ phosphor with spherical particle shape can exhibit good luminescent properties and morphology of Y2O3:Eu3+ phosphor is a more crucial factor than crystal structure to the enhanced luminescence.

Swift heavy ion irradiation induced modification in structural, optical and luminescence properties of Y2O3:Tb3+ nanophosphor

This paper reports on a comparative study on the structural, optical and luminescence properties of Y2O3:Tb3+ nano-phosphor after 150MeV Ni7+ and 120MeV Ag9+ ion beam irradiation at various fluences ranging from 1×1011 to 1×1013ions/cm2. The modifications in the structural, optical and luminescence properties of the nano-phosphor were studied before and after irradiation by using X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis diffuse reflectance (DR) spectroscopy and photoluminescence spectroscopy (PL). The TEM results show the reduction of the particle size from 75nm to 51 and 18nm after ion irradiation with the Ni7+ and Ag9+ ions, respectively. The calculations from XRD data suggest that the particles consisted out of smaller crystallites of 64, 43 and 10nm for the virgin, Ni7+ and Ag9+ irradiated samples, respectively. DR spectra show a blue shift in the absorption band, resulting in an increase in the band gap after ion irradiation. An increase in the intensity of the PL peaks without any shift in the peak positions was observed with the increase in the ion fluence. The relative intensity ratios of the different emissions at 485, 545, 585 and 625nm due to the characteristic transitions for Tb3+ (5D4→7F6, to 5D4→7F55D4→7F4 and 5D4→7F3), however, changed with the ion fluence. The color coordinates of the Y2O3:Tb3+ therefore changed to the deep green light region with the increase in the ion fluence. The magnitude of the effect of the irradiation is greater in the case of the Ag9+ ions than the Ni7+ ions due to the high electronic energy loss of the Ag9+ ions in the nano-phosphors. The results can be correlated on the basis of linear energy transfer of the irradiated ions.

Synthesis and Luminescent Properties of Y2O3: Tb3+, Dy3+ Nanorods

The Y2O3: Tb3+, Dy3+ nanorods were synthesized by hydrothermal method. Their structure and micromorphology were analyzed by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The photoluminescence (PL) properties of Y2O3: Tb3+, Dy3+ phosphor nanorods were investigated. Upon excitation with ultraviolet (UV) irradiation, it is shown that there is a strong emission band at around 545 nm, corresponding to 5D4-7F5 transition of Tb3+ and the band at 571 nm corresponding to the hypersensitive transition 4F9/2–6H13/2; the band at 485 nm corresponds to the 4F9/2–6H15/2 transition. Tb3+, Dy3+ ions with different proportion are induced into the Y2O3 lattice; the emission intensity and color of nanorods reveal regular changing in the separation of light-emitting.

Effect of doping concentration and annealing temperature on luminescence properties of Y2O3:Eu3+ nanophosphor prepared by colloidal precipitation method

Eu3+ doped Y2O3 nanophosphors have been synthesized using the simple colloidal precipitation method. Doping of Eu3+ ions in host yttria lattice has been achieved through slow re-crystallization process under wet-chemical conditions followed by annealing at high temperatures (300–1400°C). The nanophosphors were characterized by using powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), atomic force microscopy (AFM) and spectrofluorometer techniques. XRD analysis reveals formation of pure cubic phase of Y2O3 in samples annealed at 700°C or above. Further, the XRD data was successfully used to retrieve the crystallite size and size distribution from powder samples using the FW((1/5)/(4/5))M method. Crystallite size (11–50nm) extracted from XRD has been found to be consistent with AFM measurements. The PL emission spectra of nanophosphors show bright red emission at 612nm due to hypersensitive electric dipole (ED) 5D0–7F2 transition of Eu3+ ions in Y2O3 lattice. Further, photoluminescence studies indicate that optimum value of the Eu3+ to get best luminescence properties is 12at%. Surface conjugations of these nanophosphors with water soluble dextran biomolecules have also been performed. Surface conjugated rare earth nanophosphors have great potential for bio-applications.