This study features structural and photometric aspects of a down-converted green emanating erbium (Er3+) activated nanophosphor synthesized via a versatile and environmentally benign urea aided ...solution combustion procedure. The powder X-ray diffraction pattern (PXRD) of optimal sample SrGd1.96Er0.04Al2O7 studied qualitatively by employing the Rietveld refinement practice, disclosed the tetragonal crystal phase with space group 14/mmm (139), consisting grains of size 50.03 nm. Surface morphology and grain size of nanopowders were well investigated by electron microscopy practices like scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). SEM micrograph gave clear insight that Er3+ doped nanophosphors possess slightly agglomerated particles with pores, voids and cracks due to high pressure breakout of gases while combustion synthesis. TEM and SEM images revealed the size of nanoparticles in the ambit of 40–60 nm which was in coherence with that obtained from the scherrer's equation, while the inter-fringes distance corresponding to diffraction plane (116) was calculated to be 0.27 nm from the HRTEM image. The desired nanophosphor showed brilliant green emission with an intense peak at 551 nm attributed to 4S3/2 → 4I15/2 transition of Er3+ ions, as analyzed through photoluminescent (PL) emission spectra monitored via near ultraviolet excitation wavelength (381 nm) with an optimal doping concentration of 2.0 mol%. Advanced photometric features like CIE color coordinates (0.3017, 0.6043), CCT (6032K), and color purity (76.52%) confirmed their green glow and are found to be in harmony with standard green emission. The study offers a luminous cool green emanating component for the fabrication of WLEDs and advanced optoelectronic appliances.
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•SrGd2Al2O7:Er3+ nanophosphors were prepared via combustion procedure.•Absolute crystal phase was analyzed using XRD assisted Rietveld Refinement technique.•The new down-converted nanophosphors exhibit excellent green luminescence.•CIE chromaticity co-ordinates, CCT and color purity were inspected thoroughly.•Potential candidate for cool WLEDs, lasers and optical sensors.
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•Five new europium (III) complexes are synthesized and characterized by adopting various advanced techniques.•TG/DTG analysis reveals the thermal stability of complexes up to ...245 °C.•The PL spectra of the complexes are devoid of any ligand fluorescence and phosphorescence confirms efficient energy transfer.•From their emission spectra colour coordinate values and Judd- Ofelt intensity parameters are calculated and analyzed.•The colour coordinate values of all complexes depict pure red emission.
Europium complexes attracted generous interest devoted to their red colored emission for illuminising the grounds of organic light-emitting diodes. In this series, five europium complexes (C1-C5) have been synthesized with Ethyl 4-(4-methoxyphenyl 2, 4-dioxobutanaote) (dioxoester) as primary ligand and neocuproine (neo), 2, 2′-bipyridyl (bipy), bathophenanthroline (batho) and 1, 10-phenanthroline (phen) as ancillary ligands. All these complexes are characterized by adopting various investigative techniques. They show europium-centered luminescence as a characteristic red colored emission peak at 618 nm due to (5D0-7F2) -transition. The luminescence lifetime and internal quantum efficiencies of complexes are predicted by using photophysical data and Judd-Ofelt analysis. The monoexponential behavior of the decay curve suggests the presence of a single chemical atmosphere in the inner coordination sphere of the europium ion. TG/DTG analysis reveals the thermal stability of complexes up to 245 °C. The CIE color coordinates, color purity and asymmetric ratio of complexes confirm the emission in the red region of the visible spectrum.
Preparation and optoelectronic features of five new samarium (III) binary and ternary complexes with 5-(4-methylphenyl)-2- furoic acid (L) are reported in the solid state. The structures of the ...complexes Sm(L)3.H2O (C1), Sm(L)3neocuproine (C2), Sm(L)3bipyridyl (C3), Sm(L)3bathophenanthroline (C4) and Sm(L)3 phenanthroline (C5) are analyzed by elemental analysis, EDAX, FTIR, 1H NMR and thermogravimetric analysis (TGA). The photo-emission spectra exhibit well-defined narrow emission peaks that originates from 4G5/2→6HJ (J = 5/2, 7/2, 9/2) transitions of the samarium ion. All complexes exhibit good thermal stability with attractive photophysical features. The CIE color coordinates based on photoemission spectra are approximate with the National Television Standard Committee (NTSC) standard value for orange color. Especially the ternary complexes C2–C5 displayed enhanced photoluminescence intensity and longer luminescence lifetime value as compared to the binary complexes C1, with the introduction of the electronic donating 4-methyl group and the enlarged π-conjugated phenyl group. All the results indicate that these complexes are promising candidate as orange component in fabrication of organic light emitting diodes (OLED).
•Five new samarium (III) complexes are synthesized and characterized.•TG/DTG analysis reveals the thermal stability of complexes up to 151 °C.•Emission spectra consists of three well identified peaks of Sm (III) ion.•Complexes show bright orange emission as validated by chromaticity characteristics.
Five novel bright orange color emitting Sm(III) complexes (C1-C5) have been synthesized via energy efficient and cost effective solution precipitation method with 5-phenyl 2-furoic acid as primary ...organic sensitizer and nitrogen donor neocuproine, 2, 2- bipyridyl, bathophenanthroline, and 1,10-phenanthroline as secondary ligands. All the newly synthesized metal complexes are thoroughly characterize to examine the appropriateness of the organic ligand for the sensitization process. All the outcomes of the various advanced and fundamental spectroscopic techniques validate the bonding of carboxylate group with the Sm(III) ion. The luminescence spectra reflects the dominance of magnetic dipole transition which designate the occurrence of harmonized chemical environment in the coordination sphere which is further validated by enhanced values of intensity ratio. These complexes possess suitable thermal stability with excellent photoluminescent features as confirmed by thermogravimetric analysis and photoluminescence studies. The luminescence lifetime of samarium complexes C2-C5 is relatively long due to the synergistic effect presented by ancillary ligands. The emission color of the synthesized complexes show shift from orange to bright orange red color which is displayed through CIE color coordinates.
Our present technological society needs the assistance of lanthanide luminescence in almost every field to meet the global energy demands. In present research work we have synthesized five (one ...binary and four ternary) 5-(4-methylphenyl)-2- furoic acid based Eu(III) complexes with ancillary ligands, namely, aqua (H
2
O), neocuproine (neo), 2, 2’-bipyridyl (bipy), bathophenanthroline (batho) and 1, 10-phenanthroline (phen). The spectroscopic analysis and photophysical features are characterized by the use of different investigative techniques. All the findings obtained from EDAX, elemental (CHN) analysis, FT-IR, NMR, UV–visible spectroscopy declared the coordination of ligand binding sites with the europium ion. These Eu(III) complexes possess good thermal stability and excellent optoelectronic features as predicted with the help of TGA and PL analysis. Diffuse reflectance spectral studies confirm their applications in the wide band gap semiconductors. The Judd–Ofelt analysis and monoexponential behavior of lifetime reveals the existence of asymmetric and single local environment around europium ion. All the complexes show sharp red emission validated by CIE color coordinates, color purity, asymmetric ratio and CCT values. SEM analysis tells that the bulk of these complexes comprised of spherical shaped particles with uniform distribution.
The ongoing ambitious progression in the illumination sector to design the iconic WLEDs has bestowed an impetus to manufacture novel and eco-friendly nanophosphors (NPs). In this pursuit, we have ...presented cool white light-emitting single-phase crystalline Dy
3+
-doped Ca
9
Y(PO
4
)
7
i.e., CYP:Dy
3+
nanophosphors synthesized via a facile, economical, and non-toxic solution combustion (SC) technique. The crystal structural details regarding phase formation and crystallite size of CYP:Dy
3+
was inferred using powder x-ray diffraction (PXRD), which suggests the structures are in a rhombohedral phase with the R3c space group. The Kubelka–Munk model was used to evaluate the optical band gap of 4.18 eV, thus revealing their desired optical quality and semiconductor nature. Transmission electron microscopy (TEM) showed agglomerated particles with irregular dimensions with an average size ranging from 40 nm to 65 nm. Photoluminescence studies indicated the emission of visible photons under high energy irradiation with the bands at
4
F
9/2
→
6
H
13/2, 15/2
, due to intra-configurational transitions of Dy
3+
ions. The phosphor was located in the white region with the Commission Internationale de I'Eclairage (CIE) chroma coordinates of (0.295, 0.336). Thus, the presented work carves an avenue for the synthesis of single-phase nanophosphors with economical and environmental advantages, along with a proposal to boost the advancement in WLEDs relevant to industrial prospects, thus generating more revenue.
Graphical Abstract
To improve current multiphase white light emitting diodes (WLEDs), a novel series of five complexes consisting of one binary and four ternary complexes that emitted cool white light was successfully ...synthesized using a chelating tetradentate ligand and auxiliary ligands, i.e. 5,6‐dimethyl‐1,10‐phenanthroline, 1,10‐phenanthroline, 4,4′‐dimethyl‐2,2′‐bipyridyl, and 2,2′‐bipyridyl. The series was examined structurally using elemental analysis, Fourier transform infrared spectroscopy, energy dispersive X‐ray analysis, ultraviolet–visible spectroscopy, and proton nuclear magnetic resonance spectroscopy. These complexes had the appropriate thermal stability required for the generation of white organic LEDs (WOLEDs). Dysprosium (III) (Dy3+) ion complexes demonstrated the characteristic emission peaks of blue colour at 482 nm and yellow colour at 572 nm, respectively, when excited using near ultraviolet light. Band gap, refractive index, and decay lifetime of the optimized samples were recorded as 2.68 eV, 2.12, and 1.601 ms, respectively. Correlated colour temperature value (7875 K), Commission International de l'Eclairage coordinates (0.300, 0.294), and colour purity (21.04 × 10−2) of the optimized complex were near to those of white illuminants as defined by the National Television System Committee. These complexes had promise as commercial LEDs for the advanced optoelectronics devices, especially as WOLEDs for illumination applications.
In this research work we reported a novel series of five complexes consisting of one binary and four ternary complexes that emitted cool white light and that were successfully synthesized using chelating tetradentate ligand and auxiliary ligands. The complexes were analyzed systematically by different techniques. Photoluminescence studies as well as colour purity and correlated colour temperature values confirmed cool white emission of the complexes in visible region. The energy transfer mechanism confirmed effective complexation of ligands with metal ions.
The present research work entails the synthesis of one binary and four ternary red light−emitting Eu (III)‐based complexes with 3‐benzylidene‐2,4‐pentanedione as the main ligand and ...1,10‐phenanthroline, bathophenanthroline, neocuproine, and 4,4′‐′dimethyl‐2,2′‐′bipyridyl as auxiliary ligands. The metal–organic framework of the series was elucidated using energy dispersive X‐ray analysis, elemental analysis, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance. This Eu (III) series exhibits optimum thermal stability, making them a promising candidate for organic light‐emitting diodes. On the basis of emission spectra, their optical parameters such as nonradiative and radiative decay rates, luminescence decay time, intrinsic quantum efficiency, and Judd–Ofelt intensity parameter were determined. The monocentric luminescence and Judd–Ofelt parameters reveal the absence of symmetry around the europium center. CIE chromaticity coordinates, correlated color temperature values, color purity, and asymmetric ratios authenticate the color coordinates of the complexes in red region. Optical band gap values lie within the range of wide band gap semiconductors, indicating their utilization in military radars and biological labeling.
In this work, we have reported five red light emitting Eu(III) complexes utilizing bidentate ligand and auxiliary ligands. The synthesized complexes are analyzed by EA, FT‐IR, NMR, UV, DR, PL and TG analysis. PL and CIE investigation of the complexes depicts the red coloured emission. The energy transfer phenomenon reveals the efficient complexation of ligands with Eu(III) ion.
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•CLP: Dy3+ nanophosphors were synthesized via solution combustion synthetic procedure at a low cost.•CIE coordinates lie close to those required for commercial white light ...emission.•CLP: Dy3+ nanoparticles provide the desired white emission for industrial lighting applications.
Globally, the energy consumption has accelerated, which has driven the research to increase sustainable energy sources. In this context, this is the first report on the exploration of the structural and photometric aspects of Dy3+ doped Ca9La(PO4)7 i.e., CLP: Dy3+ nanophosphors for designing WLEDs economically. Herein, the solution combustion method was utilized for fabricating the desired nanophosphor, thereafter their morphological behavior, and crystallite size were studied in detail via X-ray diffraction, scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) techniques which confirmed the rhombohedral crystal architecture with R3c space group affirming the potential of the fabricated nanomaterials in optoelectronics. CLP: Dy3+nanophosphors depicted reproducible emission spectra with peaks at 4F9/2 → 6H13/2, 15/2 attributed to intra-configurational transitions of Dy3+ ions. The increasing dopant concentration beyond 20 mol % reduced the intensity of emission peaks which could be ascribed to the dipole–dipole interactions of the neighboring ions. The optical band gap of 5.38 eV derived via Kubelka-Munk relations established their role in semiconductors. Moreover, their Commission international de I’eclairge (CIE) chromaticity coordinates were studied in detail to reveal the emission color with color purity and Correlated Color Temperature (CCT) values. All the results favored and exemplified the incredible role of CLP: Dy3+ nanophosphors for emerging future prospects in advanced optoelectronic technology.
Five samarium complexes are synthesized with main ligand ethyl(4-methylbenzoyl) acetate (EMB) and secondary ligands 4,4′-dimethyl-2,2′-bipyridyl; 2,2′-bipyridyl; 1,10-phenanthroline and ...bathophenanthroline. The synthesized complexes are investigated by employing different techniques, including elemental analysis, EDX, FT-IR, NMR, TG/DTG, DR, and UV–vis absorption spectroscopy. The investigation of optical features of complexes helps to analyze their photoluminescent features. The characteristic peaks of samarium complexes under excitation of UV light are positioned at 568, 605, 650, and 693nm, and the peak responsible for vermilion emission is located at 605nm which is an intense one. Further, chromaticity coordinates, color purity, and correlated color temperature are calculated to explore vermilion color and the nature of the light of complexes. The decay curve, HOMO-LUMO energy gap, refractive index, and energy transfer mechanism are also discussed in present work.
•Five new samarium (III) complexes are synthesized using ethyl(4-methylbenzoyl) acetate (EMB) as main ligand and dmbipy, bipy, batho and phen as secondary ligand.•Complexes are characterized by using CHN, EDX, IR, NMR, TG-DTG, UV, DR, and PL.•Photoluminescence study, color purity and CCT values confirm emission of bright vermilion color.•The energy transfer mechanism approves the effective complexation of ligands with metal ion.
