Photoluminescence Studies Research Articles

1,1,1-Trifluoro-5,5-dimethyl-2,4-hexanedione based ternary complexes of Eu(III): Synthesis, structural and luminescence investigations

In this current study, we have synthesized four europium(III) complexes utilizing a tri-fluorinated β-diketone moiety: 1,1,1-trifluoro-5,5-dimethyl-2,4-hexanedione (TFDH) with auxiliary ligand: 2,2′- bipyridine and its derivatives. FTIR, UV–Vis and luminescence spectroscopic characterizations were implemented for evaluation of the bonding and luminous characteristics in synthesized europium(III) complexes. Eight-coordination environment around Eu3+ ion has been demonstrated by 1H NMR spectral data. Photoluminescence (PL) study of these complexes has been carried out in powdered form. Characteristic red emitting behavior of Eu(III) ion was observed corresponds to the transition of 5D0→7F2 in PL spectra of Eu(III) complexes. The CIE (Commission Internationale de l'Eclairage) chroma coordinates 1931 and CCT (Correlated Color Temperature) values were derived from the information obtained from the emission spectra. The Judd-Ofelt intensity parameters (Ωτ) and excited state deactivation time (τ) in solid state have also been estimated. In the synthesized Eu(III) complexes, the europium ion was present in a highly polarizable ligand field, as demonstrated by the higher values of Ω2. Values of band gap i.e. optical and electronic as well as the red luminous nature of prepared complexes showed up their utilization in display devices.

Effect of Lattice Disorder on Exciton Dynamics in Copper-Doped InP/ZnSexS1-x Core/Shell Quantum Dots.

InP/ZnSexS1-x core/shell quantum dots (QDs) with varying Cu concentrations were synthesized by a one-pot hot-injection method. X-ray diffraction and high-resolution transmission electron microscopy results indicate that Cu doping did not alter the crystal structure or particle size of the QDs. The optical shifts in UV-visible absorption and photoluminescence (PL) suggest changes in the electronic structure and induction of lattice disorder due to Cu doping. Ultrafast transient absorption spectroscopy (TAS) reveled that a higher Cu-doping level leads to faster charge carrier recombination, likely due to increased nonradiative decay from defect states. Time-resolved PL (TRPL) studies show longer average lifetimes of charge carriers with increased Cu doping. These findings informed the development of a kinetic model to better understand how Cu-induced disorder affects charge carrier dynamics in the QDs, which is important for emerging applications of Cu-doped InP/ZnSexS1-x QDs in optoelectronics.

Crystallization of zinc azole complex incorporated Strandberg-type cluster-based solids: Synthesis, structure and photoluminescence studies

Crystallization of zinc azole complex incorporated Strandberg-type cluster-based solids: Synthesis, structure and photoluminescence studies

Solution Processed Hybrid Lead Perovskite Films for White Light Emission and Lasing Applications

Abstract2D organic–inorganic hybrid lead halide perovskite films are fascinating optoelectronic materials for white‐light emission and lasing applications. Here, it is demonstrated that nano‐meter‐thick films of perovskites can be formed at room temperature using Langmuir–Schaefer (LS) deposition technique. In situ X‐ray measurements reveal a self‐assembly process of the 2D perovskite formation at the air–water interface. This formation process requires the presence of stearic acid monolayer on the water subphase having a solution of lead‐perovskite in dimethylformamide. Microscopy and X‐ray measurements of these nanofilms transferred onto substrates show crystalline phase formation that deviates from the known orthorhombic structure of the bulk crystals. The nanofilms exhibit novel broad optical emission with sharp band‐edge transition in temperature‐dependent photoluminescence studies. Also, their band‐edge emission is distinctly blue‐shifted compared to that of thicker 2D perovskite flakes prepared by the slow‐cooling chemical synthesis process. 2D flakes exhibit lasing that cannot be obtained in the LS nanofilms as their thicknesses are lower than the lasing wavelength prohibiting wave‐guide formation. The results show that the 2D single‐crystalline nature of the LS films and flakes are suitable materials to develop broad‐band white light emission across the entire visible range and to obtain lasing without external cavities, respectively.

Quantum yield and scintillation behaviors of lanthanum barium borate doped with Eu3+ ion scintillating glasses

Lanthanum barium borate glasses doped with Eu3+ ions were synthesized using a melt quenching method, with a nominal chemical composition of {10La2O3–20BaO-(70-x)B2O3-xEu2O3; 0.0 ≤ x ≥ 7.0} mol%. These glass samples were characterized, including assessments of their physical, structural, optical, and luminescent properties. The emission spectra, both of photoluminescence and radioluminescence studies were presented and found featuring five distinct peaks at 577 nm (5D0→7F0), 590 nm (5D0→7F1), 613 nm (5D0→7F2), 652 nm (5D0→7F3), and 701 nm (5D0→7F4). Interestingly, concentration quenching effects were observed at Eu3+ concentrations of 3.0 mol% and 5.0 mol% for photoluminescence and radioluminescence respectively. The decay time of LaBaBEu3.0 show 1.617 ms and the quantum yield reaching value of 14.16%. The CIE 1931 chromaticity coordinates of these glasses show reddish-orange color. This reddish-orange color was particularly observed when the samples were excited under a UV lamp.

Sustainable carbon quantum dots enhanced photoluminescence for bioimaging applications: An in vitro and in silico analysis

This study explores the synthesis and characterization of glucose-based carbon quantum dots (CQDs) for potential applications in the field of photoluminescence. The unique properties of CQDs are investigated, highlighting their distinct features compared to traditional carbon dots. Here, commercially available L-glucose is a precursor that has been chosen as the starting material to produce fluorescent carbon quantum dots (CQDs). The low to high quantum yield CQDs were reduced by chemical reduction method using sodium borohydride and then thiol (L-cysteine) induced for the stabilizer to stabilize rigidified reduced CQDs-L-cysteine (r-CQDs-Cys). The effect of pH and the ligand effect have been investigated for the photoluminescence (PL) studies of r-CQDs-Cys, yielding emission responses that were tuned according to the pH and ligand. The optimized CQDs to r-CQDs-Cys shows the quantum yield (QY) increased from 8.56 % to 42.72 %. The fluorescent QY of the synthesized CQDs investigated for the cytotoxicity test explicates that 90 % of the cells (MCF7) maintain their normal morphology even at higher concentrations of r-CQDs-Cys at 100 µg/mL. This Cytotoxicity test suggests that r-CQDs-Cys are non-toxic biocompatible and the binding energy value −6.8 kcal/mol of the carbon quantum dots was confirmed by in-silico studies. A total of 13 hydrogen bonds, 2 carbon bonds, and one Pi bond were formed during the interaction of the MCF7 cancer cell line with carbon quantum dots. The overall results confirmed that r-CQDs-Cys enhanced QY, fluorescence emission, and superior water solubility of the while compared to others which made them suitable for bio-imaging applications.

Pyrazolate-Bridged NHC Cyclometalated [Pt2] Complexes and [Pt2Ag(PPh3)]+ Clusters in Electroluminescent Devices.

The ionic transition metal complexes (iTMCs) [{Pt(C∧C*)(μ-Rpz)}2Ag(PPh3)]X (HC∧C* = 1-(4-(ethoxycarbonyl)phenyl)-3-methyl-1H-imidazole-2-ylidene, X = ClO4/PF6; Rpz = pz 1a/2a, 4-Mepz 1b/2b, and 3,5-dppz 1c/2c) were prepared from the neutral [{Pt(C∧C*)(μ-Rpz)}2] (Rpz = pz A, 4-Mepz B, and 3,5-dppz C) and fully characterized. The "Ag(PPh3)" fragment is in between the two square-planar platinum units in an "open book" disposition and bonded through two Pt-Ag donor-acceptor bonds, as shown by X-ray diffraction (dPt-Ag ∼ 2.78 Å, 1a-1c). 195Pt{1H} and 31P{1H} NMR confirmed that these solid-state structures remain in solution. Photoluminescence studies and theoretical calculations on 1a, were performed. The diphenylpyrazolate derivatives show the highest photoluminescence quantum yield (PLQY) in the solid state. Therefore, 2c and its neutral precursor C were selected as active materials on light-emitting devices. OLEDs fabricated with C showed a turn-on voltage of 3.2 V, a luminance peak of 21,357 cd m-2 at 13 V, and a peak current efficiency of 28.8 cd A-1 (9.5% EQE). They showed a lifetime t50 of 15.7 h. OLEDs using 2c showed a maximum luminance of 114 cd m-2, while LECs exhibited a maximum luminance of 20 cd m-2 and a current efficiency of around 0.2 cd A-1, with a t50 value of 50 min.

Morinda coreia fruits derived green-emissive nitrogen-doped carbon quantum dots: Selective and sensitive detection of ferric ions from water

Carbon quantum dot containing nitrogen has been prepared by utilizing a green biomass resource, Morinda coreia fruits, by a single step hydrothermal procedure. The spherical carbon dots are analysed by HR-TEM, XPS, FT-IR, UV–visible and photoluminescence studies. With a mean diameter of 1.99 nm, they possessed functional groups like carboxyl and amide on their surface and emit light of wavelength of 490 nm under 390 nm excitation. The fluorescent Morinda coreia carbon dots (MCCDs), whose quantum yield is found to be 17.1 %, are very sensitive to the presence of iron (III) ions with a low detection limit of 1.32 μM. Successful fluorometric determination of Fe3+ ions from tap water and borewell water were also achieved with good recovery rates. Interactions between surface groups on MCCDs and Fe3+ ions lead to the formation of a non-fluorescent complex, and a static quenching mechanism is proposed.

Tuning the electrochemical properties of ZnO through chromium doping and its suitability for supercapacitor application

ZnO nanoparticles doped with chromium (Cr) were synthesized through a simple sol gel route. The successful Cr doping into the ZnO lattice has been evidenced via several characterisation techniques i.e., XRD and XPS. A high oxygen vacancies (OV) density has been located through Photoluminescence (PL) and EPR studies for the Cr doped ZnO (1 %) (ZnCr1) sample. The high density of OV defects induced from Cr doping in ZnO lattice was considered at the origin of the improved electrochemical performances by promoting efficient electron transfer ability with intercalation process of the electrolyte's ions during charge-discharge mechanism. The ZnOCr1 electrode displays an important capacitance value (367 F.g−1), ultrahigh capacitance retention (86 %) while changing the current from 1 to 20 A·g−1, and marvellous stability of 84 % during 4000 cycles. An asymmetric supercapacitor based ZnOCr1 electrode achieves significant potential window up to 1.6 V with encouraging specific energy density. The device showcases a satisfactory specific energy of 27.1 Wh·Kg−1 at specific power of 480 W·Kg−1 and a great retention of 17 % decay after 4000 cycles at current density of 10 A g−1. This opens door to the developed ZnO-Cr1 material for its application in future supercapacitor devices.

Photoluminescence and supercapacitor applications of dysprosium doped rhombohedral silver gallium oxide nanoparticles

Dy3+ doped Silver Gallium Oxide (AgGaO2) nanoparticles (NPs) (AGO:Dy3+) are effectively synthesized via a green mediated route using Aloe vera gel extract as a reducing agent, followed by calcination at 600 °C for 3 h. Powder X-ray diffraction (PXRD), Fourier transformation infrared (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), photoluminescence (PL), and electrochemical studies were employed to confirm the synthesis, structural, luminescence, and supercapacitor properties of the NPs. The diffraction peaks of the synthesized samples possess a trigonal structure within a rhombohedral system. The surface morphology consists of a few irregular, a few hexagonal, and a few rice grain-structured NPs. The changes in the agglomeration were observed with variations in the dopant concentration. The direct energy band gap increases from 3.11 to 3.13 eV with an increase in the dopant concentration. Under 276 nm excitation, the PL spectra of AGO:Dy3+ nanophosphors reveal robust emission peaks attributed to 4F9/2→6F15/2 (480 nm) and 4F9/2→6F13/2 (565 nm). The confirmed critical distance signifies that energy transfer occurs through a multipolar interaction mechanism. The CIE chromaticity diagram illustrates the emission of yellowish green light from the phosphors. These investigations indicate the potential applications of AGO:Dy3+ nanocrystals in a light-emitting diode as a nanophosphor material. Nanocrystals in light-emitting diodes as a nanophosphor material. Thorough electrochemical investigations, encompassing cyclic voltammetry, were conducted to decipher redox reactions, electrode kinetics, and electrochemical behavior. The precise elucidation of ion transport kinetics was achieved through Electrochemical Impedance Spectroscopy (EIS), while the determination of supercapacitance values was accomplished via Galvanostatic Charge-Discharge (GCD) analysis. The supercapacitance values exhibited a remarkable range from 76.177 to 111.53 F/g, underscoring their sensitivity to dopant concentration. Consequently, the material synthesized in this groundbreaking study exhibits substantial promise for diverse applications, spanning from energy storage materials to the dynamic landscape of display technology. Electrochemical studies.

Two-step synthesis of antimony sulfide thin films: enhancement in physical properties through sulfurization

Recently, there has been an increase in the use of antimony sulfide (Sb2S3) in Si-based tandem solar cells as a potential absorber material for top sub-cells. The choice of the material stems from the favoured properties such as appropriate bandgap, simple binary composition, nontoxic elements, and long-term stability. However, the physical properties and practical applicability of these materials depend largely on their synthesis conditions. In this work, we investigate the role of sulfurization on the structural, morphological, compositional, and optical properties of Sb2S3 thin films deposited on soda-lime glass via a thermal evaporation technique. Sulfurization was performed on the as-prepared thin films in a customized Chemical Vapor Deposition (CVD) chamber at five different temperatures. Analysis of the crystallinity of the film using the x-ray diffraction technique illustrates the transformation of the film from impure, poor crystalline phase to phase-pure, and highly crystalline orthorhombic structure due to sulfurization. Scanning electron microscopic investigations of the samples revealed better grains with nanorods on the surface at a temperature of 400 °C. For the samples investigated here, the energy values estimated via density functional theory (DFT) calculations agreed well with the experimental data obtained from UV-visible absorption spectral studies. Additionally, it was observed that the desired near-stoichiometric Sb2S3 thin films could be achieved via sulfurization, and the presence of Sb2S3 in all samples was confirmed via Raman spectroscopic studies. Additionally, the defects and trap states of the prepared films were investigated using photoluminescence studies, and donor and acceptor defects were identified. Our study revealed that sulfur rich Sb2S3 films prepared at a sulfurization temperature of 400 °C produced the desired structure, morphology, and optical qualities for future photovoltaic applications.

Revealing localized excitons in WSe2/β-Ga2O3

We have investigated the optical and magneto-optical properties of monolayer (ML) WSe2 on flakes of β-Ga2O3 under high magnetic fields. Remarkably, sharp emission peaks were observed and associated with localized excitons related to point defects. A detailed study of low-temperature photoluminescence (PL) and magneto-PL under high perpendicular magnetic field up to 9 T was carried out. Several sharp emission peaks have shown valley g-factors values close to −4, which is an unusual result for localized excitons in WSe2. Furthermore, some PL peaks have shown higher g-factor values of ≈−7 and ≈−12, which were associated with the hybridization of strain localized dark excitons and defects. The reported results suggest that β-Ga2O3 is, indeed, a promising dielectric substrate for ML WSe2 and also to explore fundamental physics in view of possible applications in quantum information technology.

Synthesis and characterization of bi-functional Cu and Ni co-doped ZnO photocatalysts for organic pollutant degradation and antimicrobial activity

The study of visible light active photocatalysts for organic pollutants degradation and antimicrobial activity has gained significant attention in recent years. Herein, we report the synthesis of pure ZnO, Ni-doped ZnO (Ni-ZnO), Cu-doped ZnO (Cu-ZnO), and Cu and Ni co-doped ZnO (CuNi-ZnO) photocatalysts via a facile coprecipitation method. These photocatalyst materials were characterized using various analytical techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscope (HR-TEM), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–Vis), photoluminescence (PL), and total organic carbon (TOC) analysis. XRD patterns confirm the presence of a mixed phase in the CuNi-ZnO sample. The presence of Cu, Ni, and Zn in CuNi-ZnO was verified through the XPS spectra. The nanoparticle-like morphology of the CuNi-ZnO photocatalyst was confirmed using HRTEM analysis. The FTIR spectra reveal the chemical bonds present in the materials. UV–visible spectroscopy was employed to determine the band gap of the materials, revealing a value of 3.10 eV for CuNi-ZnO. The mitigation in recombination of excited electrons (e−) and holes (h+) in CuNi-ZnO is validated through photoluminescence (PL) studies. The synthesized materials were used for the degradation of Indigo carmine (IC) dye and antimicrobial activity. The results showed that the optimized CuNi-ZnO sample displayed a better visible light photocatalytic performance (93.32 % IC dye degradation efficiency in 60 min) than the other samples. A notable degree of mineralization was observed with a reduction in total organic carbon (TOC) reaching 65.91 %. Additionally, the photocatalyst showed antimicrobial activity against both S. aureus and E. coli. Furthermore, a plausible visible light photocatalytic mechanism was proposed for the degradation of IC dye using the CuNi-ZnO photocatalyst.

Synthesis, Characterization, Dielectric, and Electrical Conductivity Studies of Zinc Oxide Nanoparticles

A co-precipitation technique is used to synthesize of ZnO nanoparticles. The synthesized ZnO nanoparticles were characterized by UV-visible spectroscopy, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), photoluminescence, Fourier-Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD). The size of the nanoparticles was wide-ranging from 1 nm to 100 nm, corresponding to the HR-TEM analysis. The photoluminescence study of ZnO nanoparticle shows emission in the UV region. The particle dimension of ZnO nanoparticle has also been studied through XRD. Dielectric spectroscopy of synthesized ZnO NPs pellet has been studied at a wide frequency range 10−1 to 105 Hz. The capacitance and dielectric permittivity of ZnO nanoparticles drop continuously with frequency as dipoles have less time to align in the field. Dielectric permittivity of ZnO pellets increase up to 5 mm thickness and subsequently drop, perhaps due to raise in resistivity. The dielectric loss of ZnO pellet has been examined as a function of frequency. The electrical conductivity of ZnO nanoparticles rise exponentially with frequency. Based on the dielectric studies, the dielectric permittivity and electrical conductivity of ZnO are highly depending on thickness and frequency range. The percolation threshold of ZnO pellets has been found between 4-5 mm thicknesses.

Unveiling the Structural and Optical Properties of Samarium Titanates Pyrochlore, Sm2Ti2O7

A magnetic system whose geometry prevents all pairwise spin interactions from being fulfilled simultaneously to minimize the energy is said to be frustrated. These systems are prevalent throughout all disciplines of physical and chemical study. This article reports a detailed structural and optical analysis of such frustrated Sm2Ti2O7 (STO), a pyrochlore structure. The ordered pyrochlore, STO of cubic symmetry, space group Fd3¯m [no. 227], has been synthesized using the standard solid-state reaction method. The Tauc’s plot reveals a direct band gap value of 3.8 eV from ultraviolet-visible reflectance data. Photoluminescence studies for STO using 280 nm excitation wavelength show the most intense emission peak at 395 nm, 468 nm, and other weak emissions at 368 nm, 412 nm, 430 nm, 449 nm, and 514 nm corresponding to the respective electronic transitions, indicates that the materials show photoluminescence properties. However, the unique characteristics of Sm2Ti2O7, including its wide band gap, photoluminescence, and high refractive index, make it a promising candidate for various magneto-optical, solid oxide fuel cell device fabrication applications.

Temperature-induced photoluminescence amplification of graphene oxide-polyaniline composite through interaction modulated charge transfer

This report plies the effect of temperature on the interaction of GO and polyaniline at different pH through photoluminescence (PL) studies. At neutral pH, the interaction of GO-PANI is found to be highly temperature-dependent. A ground state charge transfer (CT) from the polaronic state of PANI to the GO remained at the backbone of the photophysics. The electron transfer from PANI to GO becomes more significant at a higher temperature because of the better interaction of GO with PANI moiety through π−π stacking and hydrogen bonding. The CT-induced PL amplification at elevated temperature is originating from the recombination of the spatially separated electron in the excited state of GO and hole in the PANI. The thermodynamic parameters ΔH and ΔS have been calculated associated with the electron transfer process. The positive change in the electronic entropy due to the better delocalization overcomes the entropy change due to structural orderness that drives the electron transfer process. The intensity of different PL bands remains unaffected by the temperature at lower pH due to saturated electron transfer and lower GO-PANI interaction, whereas at higher pH the CT PL band intensity decreases with an increment in temperature, explained by the increase in GO-PANI distance.

Study of Intrachain Charge Transfer in a Blue Emissive Polyfluorene Random Copolymer.

Photophysics of a blue light-emitting fluorescent random copolymer, consisting of arylated polydioctylfluorene (aryl-F8), polydioctylfluorene (F8), and amine comonomers in a ratio of 80:15:5 is reported. In a solution of 10-6 M, solvatochromism in absorption and photoluminescence (PL) is observed with an increased lifetime of PL as the polarity of the solvent increases. Dual fluorescence is observed in the 10-9 M diluted solution, comprising a structured emission from a localized state in the aryl-F8 comonomer and a broad emission peak from the charge-transfer (CT) state at a lower energy. Emission wavelength-dependent time-resolved photoluminescence studies in different polar media confirm the presence of the emissive intrachain CT state in this copolymer. Analyzing the PL decay kinetics, we calculated the formation rate of the intrachain CT state to be ∼3.0 × 109 s-1. Repopulation of the localized state from the CT state is observed in the lower polarity medium with a rate of 7 × 108 s-1, which is almost absent for the large Stokes-shifted CT emission in the higher polarity medium. Along with the fundamental understanding of the photophysics of the random copolymer, this study suggests that the emission spectrum can be tailored by the concentration of polymer and the polarity of surrounding media.

Synthesis and Properties of Eu and Ni Co-Doped ZnS Nanoparticles for the Detection of Ammonia Gas

Zinc sulfide nanoparticles were synthesized successfully via chemical co-precipitation, both in undoped form and co-doped with Europium (Eu) and Nickel (Ni). All prepared samples exhibited cubic zinc blende structure as confirmed by X-ray diffraction (XRD). The average particle size ranged from 3 to 6 nm for both pure and (Eu, Ni) co-doped ZnS, with no alteration in the crystal structure due to Eu and Ni co-doping. However, increasing the Ni dopant concentration (0, 2, 4, & 6 at%) while maintaining a constant Eu concentration (4 at%) led to an enhancement in the crystallite size. This was further validated by transmission electron microscopy (TEM), which showed particle sizes consistent with the XRD findings (3–5 nm). Microscopic analysis via scanning electron microscopy and TEM revealed spherical agglomerated morphology for the (Eu, Ni) co-doped nanoparticles. Energy-dispersive X-ray spectroscopy spectra confirmed the stoichiometric chemical composition of ZnS: Eu, Ni. Photoluminescence studies demonstrated an increased intensity of green luminescence at 6 at% Ni co-dopant concentration. Moreover, the synthesized samples exhibited promising gas sensing properties, particularly towards ammonia gas, with good selectivity. Notably, both pure and (Eu, Ni) co-doped ZnS nanoparticles showed rapid response and recovery times at room temperature, suggesting their potential applicability in gas sensing applications.

Synthesis and Photophysical Properties of Bipolar Compound: Triphenylamine/Diazafluorene-Carbazole.

Carbazole and triphenylamine, are two well-known hole transporting units that are attached to electron transporting unit 4,5-diazafluorene in a fascinating way to bring out non-planar configuration of a molecule. The synthesized compound exhibits good thermal stability (Td > 515°C) and high glass transition temperature (Tg, 191°C). Optical bandgap (Egopt) obtained from solid state absorption spectra was calculated to be 2.93eV. Solid state photoluminescence spectra displays the emission maxima at 473nm. The emission characteristics of the compound observed in solvents of different polarity confirms the existence of intramolecular charge transfer in their excited state. Density functional theory studies reveal that HOMO and HOMO-1 localized on triphenylamine is spatially separated from LUMO of 4,5-diazafluorene, which manifest its bipolar character. The realization of long lived charge separated state upon photo-excitation from time resolved photoluminescence studies ascertains the charge transfer from triphenylamine to 4,5-diazafluorene. The experimental and theoretical analysis of the compound proved it to be a promising candidate for the fabrication of OLED devices.

Effect of Pr3+ concentration in luminescence properties & upconversion mechanism of triple doped NaYF4: Yb3+, Er3+, Pr3+

Lanthanide-doped fluoride nanocrystals (NCs) exhibit excellent optical features, including upconversion and downconversion luminescence (UCL and DCL), that can be utilized in a variety of applications. In this study, we have successfully demonstrated the photoluminescence behavior of triple-doped NaYF4: Yb3+, Er3+, Pr3+ NCs in the Vis-NIR region. Herein, highly monodisperse hexagonal phase NaYF4: Yb0.2, Er0.02, Prx nanocrystals in various Pr3+ (x = 0, 0.1, 0.5, and 1 mol %) concentration with ∼22 nm diameter synthesized by thermal decomposition technique. The photoluminescence studies for all samples were performed under 980 nm laser excitation. The luminescence intensity of Er3+ including blue (407 nm), green (520 and 540 nm), red (654 nm), and near-infrared (845 nm and 1530 nm) emissions was significantly quenched and Pr3+ emission intensity at 1290 nm (Pr3+:1G4→3H5) changes irregularly upon doping with Pr3+ ions. Furthermore, we performed the excitation power dependence and decay time analysis to investigate the energy transfer and upconversion mechanisms of samples. These findings indicate that the presence of praseodymium strongly reduces emission intensities due to abundant cross-relaxation channels. In addition, particle size is an efficient factor, shedding light on the influence of Pr3+ on the energy transfer and upconversion mechanisms of the fluorides.