Red Photoluminescence Emission Research Articles

Luminescence and dosimetry investigations of Eu(III) doped Ca2CeVO6 novel double perovskite

A novel composition of vanadate double perovskite Ca2CeVO6 doped with Eu3+ was successfully synthesized using combustion synthesis, wherein the doping levels of Eu3+ ranged from 1 to 6 mol%. The Rietveld refinement of the powder X-ray diffraction (XRD) data confirmed the orthorhombic structure of the phosphors. Scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDAX) were employed to investigate the surface morphology and elemental distribution in the phosphor, respectively. Under the excitation at 280 nm and 467 nm, the phosphor exhibited strong down-conversion red photoluminescence (PL) emission, attributed to Eu3+ transitions (5D0-7FJ, where J = 0–3) originating from its 4f states. The intensity of PL emission shows increasing trend with increasing doping concentration. However, exceeding the threshold doping concentrations led reduction in PL intensity due to multipolar interaction effects. Additionally, the Eu3+ doped Ca2CeVO6 phosphors were subjected to irradiation with a radioactive 90Sr/90Y beta source to explore their thermoluminescence (TL) properties. Post-irradiation, the phosphors displayed prominent TL glow curves, with the most intense peak at around 94 °C, followed by peaks at 160 °C and 288 °C. The TL intensity of these peaks exhibited a linear dose response within the dose range of 1 Gy–50 Gy. Besides, the TL fading and reproducibility tests showed satisfactory results. Furthermore, Tmax-Tstop experiments revealed the presence of three trap centres within the trap depth range of 0.7–2.1 eV in the Ca2CeVO6:Eu3+ phosphor. Additionally, the glow curve deconvolution (GCD) was employed to determine trapping parameters, providing valuable insights into the TL behaviour of the phosphor. Overall, the results suggest that the novel phosphor under study holds promise for its applications in lighting devices and TL dosimetry (TLD).

Circularly Polarized Photoluminescence in Chiral Hybrid Organic–Inorganic Manganese Halide Perovskites: From Bulk Materials to Exfoliated Flakes

AbstractLayered hybrid organic–inorganic metal‐halide perovskites (HOIPs) can acquire chirality from molecules incorporated into their structure showing exciting possibilities in optoelectronics and spintronics. However, researchers have focused their attention on the study of bulk compounds, namely unstable and toxic Pb HOIPs. Herein, the chiroptical properties of R‐ and S‐β‐methylphenethylammonium Mn chloride HOIPs are reported in both the bulk and the few‐layer limit as exfoliated flakes. Red photoluminescence (PL) emission originating from the octahedrally coordinated Mn2+ is observed, with a PL shift to longer wavelengths when passing from bulk to flakes. Circular dichroism and circularly polarized PL mirrored‐signals for enantiomers are found in bulk samples, while in flakes, a degree of circularly polarized emission (P) of up to 17% at 80 K is achieved, comparable to Pb‐based HOIPs. Moreover, angle‐resolved PL measurements on flakes show that the PL emission and P are isotropic. These findings highlight the potential of these HOIPs from bulk to flakes for spin‐optoelectronic applications.

Tuning of photoluminescence properties: Impact of Pr-doping in SrTiO3 crystallites

Materials having deep blue emission characteristics with a CIEy chromaticity value less than 0.1 are highly desired. Here we incorporated Pr3+ into the Sr2+ site of the Sr1-x PrxTiO3 (x=0.05, 0.075, 0.10, 0.125, 0.15, 0.20) to quench the typical red photoluminescence (PL) emission in Pr-doped compounds and tune it to a blue-emitting system. XRD analysis and structural refinement demonstrate transition from cubic to tetragonal symmetry at Pr concentrations of, x≥0.1. The contribution of oxygen vacancies in emission mechanism was investigated through XPS analysis. High-resolution FE-SEM analysis of morphological features revealed the creation of tiny grains with the appearance of micro pebbles. Under 380 nm UV illumination a narrow-band blue emission peak FWHM of 19.3 nm was obtained at 428 nm for x=0.05. CIE plots were used to examine the quality of emission peaks and samples show CIEy less than 0.1. This blue emission is crucial for lighting and display applications.

HfTiO4 transparent thick film phosphors activated with Eu3+, Dy3+, and Tb3+ ions

Hafnium (Hf)-based double oxides show promise as high-efficiency scintillators due to large effective atomic numbers and high relative density. However, the preparation of these scintillation crystals is challenging due to their high melting points and incongruent melting behavior. In the present study, we demonstrated that the chemical vapor deposition (CVD) of single-phase HfTiO4 films on quartz glass substrate was successfully deposited at temperatures ranging from 973 to 988 K, with a TiO2 molar ratio in the precursor vapor of 25–45 mol% TiO2. The deposition rate of HfTiO4 reached 36 µm h−1. The films exhibited an in-line transmittance of 78 % relative to the raw glass substrate at a wavelength of 600 nm. When activated with Eu3+, Dy3+, and Tb3+ ions, the HfTiO4 films displayed red, yellow, and green photoluminescence emissions originated from the 4f–4f transitions of each trivalent rare-earth ion under ultraviolet light irradiation. HfTiO4 exhibited no intrinsic background emission, suggesting that the addition of a selected activator could yield a phosphor with the desired emission color range.

Polymorphism and Red Photoluminescence Emission from 5s2 Electron Pairs of Sb(III) in a New One-Dimensional Organic-Inorganic Hybrid Based on Methylhydrazine: MHy2SbI5.

We explore the crystal structure and luminescent properties of a new 1D organic-inorganic hybrid, MHy2SbI5, based on methylhydrazine. The compound reveals the red photoluminescence (PL) originating from the 5s2 electron pairs of Sb(III) as well as complex structural behavior. MHy2SbI5 crystalizes in two polymorphic forms (I and II) with distinct thermal properties and structural characteristics. Polymorph I adopts the acentric P212121 chiral space group confirmed by SHG, and, despite a thermally activated disorder of MHy, does not show any phase transitions, while polymorph II undergoes reversible low-temperature phase transition and high-temperature reconstructive transformation to polymorph I. The crystal structures of both forms consist of 1D perovskite zig-zag chains of corner-sharing SbI6 octahedra. The intriguing phase transition behavior of II is associated with the unstable arrangement of the [SbI5]2-∞ chains in the structure. The energy band gap (Eg) values, estimated based on the UV-Vis absorption spectra, indicate that both polymorphs have band gaps, with Eg values of 2.01 eV for polymorph I and 2.12 eV for polymorph II.

Photoluminescence and thermoluminescence kinetic features of Eu3+ doped Sr2YVO6 double perovskite phosphor

Through traditional high-temperature combustion synthesis, a series of luminescent orange-red emitting Sr2YVO6:Eu3+ double perovskite phosphors were prepared, and their luminescence properties were examined. Through X-ray diffraction (XRD) and Rietveld analysis, the monoclinic crystal structure of all prepared Sr2YVO6:Eu3+ phosphors were confirmed. Scanning electron microscopy (SEM) was used to analyse the morphology of the phosphor. Under 320 nm excitation, Eu3+ doped Sr2YVO6 phosphors exhibit very strong red photoluminescence (PL) emission bands at 595 nm, 616 nm and 620 nm as well as distinct red emission bands at 653 nm and 699 nm, which are originated due to the 5D0-7FJ (J = 1,2,3,4) transition of Eu3+. A series of phosphor also exhibit orange-red emission at 595 nm, 612 nm, 616 nm and 620 nm under the excitation wavelength of 396 nm. High color purity of the phosphors is revealed by calculated color purity and excellent chromaticity coordinates, which also confirms the presence of far-red luminescence emission. After the irradiation of the phosphors at various beta doses via 90Sr/90Y beta source, the thermoluminescence (TL) studies of Eu3+ activated Sr2YVO6 phosphors was conducted. Exposer of beta irradiation revises a prominent TL glow curve at 124 °C with a small hump at around 290 °C, indicating the development of different trap centres in the phosphor. As the dose of beta radiation increased, a linear dose response was observed in TL intensity. Computerised Glow Curve Deconvolution (CGCD) method and Chen's Peak Shape Method (PSM) were used to determine the activation energies and trapping parameters of TL glow curves. According to CGCD fitting of TL glow curves, it is found that all glow curves consist of five deconvoluted peaks, which follows general order kinetics. Activation energies calculated through different methods were comparable and significant.

Near-infrared photoluminescence radiation from the interface of an annealed ZnO nano thin film/silicon heterostructure array

In this study, the photoluminescence (PL) features of an annealed ZnO nano thin film/silicon heterostructure array were investigated. PL spectra were observed, which were closely related to the annealing temperature and covered visible–near infrared (NIR) region among 500–900 nm (1.37 eV–1.59 eV), especially two unexpected NIR peaks at 1.44 eV, 1.57 eV were detected. silicon array was synthesized by hydrothermal corrosion by using the solution composed of ferric nitrate and hydrofluoric acid. A regular array surface was obtained and exhibited a red PL emission with a slight position shift as the excitation wavelength varied. Oxygen defects in the array structure and silicon nanoparticles were responsible for the red PL. ZnO nano thin film/silicon heterostructure array was prepared by heating the Zn film coated array, which was obtained by magnetron sputtering. As the heating temperature increased to 350–400 °C, the PL intensity of the ZnO nano thin film/silicon heterostructure array decreased to approximately half that of the original, and the orange-red PL peaks was substituted by NIR radiations gradually. The models of electrons transition at the interface were analyzed to explain the emissions. The results demonstrated that the potential of ZnO/silicon heterostructure array as a NIR-emitting material.

Solid-state synthesis of cesium manganese halide nanocrystals in glass with bright and broad red emission for white LEDs.

Recently, lead halide perovskite nanocrystals (NCs) have attracted extensive attention due to their unique optical properties. However, the toxicity of lead and the instability to moisture obstruct their further commercial development. Herein, a series of lead-free CsMnX3 (X = Cl, Br, and I) NCs embedded in glasses were synthesized by a high temperature solid-state chemistry method. These NCs embedded in glass can remain stable after soaking in water for 90 days. It is found that increasing the amount of cesium carbonate in the synthesis process can not only prevent the oxidation of Mn2+ to Mn3+ and promote the transparency of glass in the 450-700 nm region, but also significantly increase its photoluminescence quantum yield (PLQY) from 2.9% to 65.1%, which is the highest reported value of the red CsMnX3 NCs so far. Using CsMnBr3 NCs with a red emission peak at 649 nm and full-width-at-half-maximum (FWHM) of 130 nm as the red light source, a white light-emitting diode (LED) device with International Commission on illumination (CIE) coordinates of (0.33, 0.36) and a color rendering index (CRI) of 94 was obtained. These findings, together with future research, are likely to yield stable and bright lead-free NCs for the next generation of solid-state lighting.

Crystallization and photoluminescence properties of Er-doped microspheres with ytterbium-aluminium garnet composition

The ytterbium-aluminate microspheres with yterbium-aluminium garnet composition doped by 0.25, 0.5, 0.75, 1.0, 3.0 and 5.0 mol.% of Er2O3 were prepared by combination of sol-gel method and flame synthesis. The prepared systems were mostly X-ray amorphous with the presence of traces of ytterbium-aluminium garnet phase (YbAG), and ytterbium oxide. The thermal analysis of prepared systems shows crystallization of the prepared systems in the temperature interval 914–984 °C in one or two steps, depending on the Er content. Ytterbium aluminate garnet was found to crystallize as the prevailing phase in all heat-treated samples. An almost pure red up-conversion photoluminescence emission with the intensity influenced by the Er2O3 content was observed in prepared systems.

Ultrathin 2D Eu3+@Zn-MOF Nanosheets: A Functional Nanoplatform for Highly Selective, Sensitive, and Visualized Detection of Organochlorine Pesticides in a Water Environment.

Facile and rapid detection of residual organic pesticides on the fruits and vegetables has recently drawn increased attention in the food safety field. Herein, a surfactant-assisted solvothermal route with subsequent post-modification was designed for the preparation of Eu3+-functionated Zn-BDC ultrathin nanosheets (labeled as Eu3+@Zn-MOF-NS, BDC: 1,4-benzenedicarboxylate) with the thickness of 5 nm. The as-obtained Eu3+@Zn-MOF-NS could be homogeneously dispersed in aqueous systems to form a highly-stable collosol. Under the UV excitation of 325 nm, the as-obtained Eu3+@Zn-MOF-NS displayed red photoluminescence emission of Eu3+ ions, which could be notably quenched by an organochlorine pesticide, 2,6-dichloro-4-nitroaniline (DCNA), without interferences from ions, organic small molecules, and other pesticides. The detection limit and Ksv were 0.17 μM (35 ppb) and 3.2 × 105 M-1 in the water system, respectively. Moreover, the present 2D Eu3+@Zn-MOF sensor was also employed for the detection of DCNA in Chaohu Lake water and tap water and in apple, cabbage, and pakchoi samples with the relative standard deviation (RSD) ranging from 4.74 to 9.77%. Further investigations revealed that the competitive absorption between DCNA and the as-obtained Eu3+@Zn-MOF-NS resulted in the fluorescence quenching of the probe.

Triarylazoimidazole-ZnII, CdII, and HgII Complexes: Structures, Photophysics, and Antibacterial Properties

Novel triarylazoimidazoles containing strong electron donors (p-NEt2) or acceptors (p-NO2) by the azoaryl group, and their group 12 metal complexes were synthesized and fully characterized, including X-ray analysis for several complexes. Novel complexes exhibit red photo-luminescence emission (Φ up to 0.21) in a solution. Moreover, the antibacterial activity of complexes was tested against Gram-positive microorganism S. aureus and Gram-negative microorganism E. coli.

Synthesis and Photoluminescence Properties of Pr3+-Doped Ba0.5Ca0.5TixZr(1-x)O3 Perovskite Diphasic Ceramics Obtained by the Modified Pechini Method.

The Pr3+-doped solid solutions from (Ba,Ca)(Ti,Zr)O3 (BCTZO) system were successfully synthesized using an efficient and low-energy consuming route—the Pechini method combined with the sintering at relatively low temperature (1450 °C). The obtained materials were characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The dielectric properties were systematically studied. The Pr3+-doped BCTZO diphasic material generates intense and broad red photoluminescence (PL) emission at room temperature. The optical properties were significantly improved with the Ti4+ substitution by Zr4+ ions. As a result, the Pr3+-doped (Ba,Ca)(Ti,Zr)O3 ceramics is a promising candidate for environmentally friendly, multifunctional material by combining good dielectric and photoluminescent properties with prognosis for the manifestation of strong photoluminescent and mechanoluminescent effects.

Photosynthetic-bacteria-derived red emissive carbon dots with low toxicity for lysosomal imaging

A novel red emissive carbon dots (CDs) derived from photosynthetic bacteria are synthesized successfully via a simple microwave–assisted hydrothermal process. The CDs exhibit good water solubility, biocompatibility, and red photoluminescence emission with an absolute quantum yield of 15.17% in water. More importantly, 5 mg/ml CDs present low toxicity after co–cultured with human umbilical vein endothelial cells (HUVECs) and HeLa cells. Furthermore, the red emissive CDs can clearly image the HUVECs and HeLa cells within 10 min and maintain stable emission for 1 h. It is also proved that the organelle of CD imaging is mainly lysosome. This work provides a new method to prepare long–wavelength fluorescence–emission CDs and explores a new material with potential applications in the biomedical field.

Electric field-induced photoluminescence quenching in Pr-doped BNT ceramics across the MPB region

Piezophotonics is a great interesting field of physics that has led to a number of important technologies, such as light source, smart sensors, and mechatronics. In this work, we reported Pr-doped (Bi0·5Na0.5)TiO3-based lead-free ceramics with strong red photoluminescence emission and large strain response (d33∗ = 460 pm/V, S = 0.32 %). The PL emission can be quenched by decreasing the intensity by 93 % after electrical polarization (E = 50 kV/cm). The local structure and electric field-induced structural changes were systematically investigated to reveal the significant distinction in photoluminescence properties caused by electrical polarization. The results indicated that polarization treatment eliminates the structural inhomogeneities and establishes a long-range ferroelectric tetragonal and rhombohedral distortion. The crystal structure transformed irreversibly from a non-ergodic to a normal ferroelectric state. PL quenching originated from the decreased distortion of octahedral due to the transition from a non-ergodic state to a highly ordered symmetrical structure. Meanwhile, the enlarged domain structure contributed to the photoluminescence quenching effect. Our findings demonstrate that an electric field can be a robust tool for adjusting the photoluminescence property and provide insights into the relationship between the structure and PL properties of BNT-based ceramics under an external stimulus.

Band gap tailoring, structural and optical features of MgS nanoparticles: Influence of Ag+ ions

Ag+ ions incorporated MgS nanoparticles were synthesized by the co-precipitation method. X-ray diffraction (XRD) spectra revealed that the samples had a cubic structure and the transmission electron microscope (TEM) pictures confirmed the spherical shape and size of the particle. The particle size was ranged from 11 nm to 15 nm. The average size of the particles was decreased for the increase of Ag+ ions concentration. Scanning Electron Microscope (SEM) photographs disclosed the surface morphology of samples. The agglomeration of the samples was reduced in the higher doping concentration. Energy Dispersive X-ray (EDX) and Fourier Transform Infrared (FTIR) analysis were utilized to verify the presence of elements as per the stoichiometry ratio. UV–vis absorption was increased due to the incorporation of Ag+ ions and better transmittance was offered for Ag = at. 2 %. The optical band gap was blue-shifted for Ag+ ions incorporated MgS nanoparticles. High intense strong red photoluminescence (PL) emission was exhibited at 660 nm by MgS:Ag for Ag = 2 at.%. The shifting of PL peaks to higher wavelength indicates the Ag+ ions incorporation. The shallow donor defects produced PL emission in a strong red region. The red emission may also be ascribed to the electron transition in high energy levels.

FRET processes of bi-fluorophoric sensor material containing tetraphenylethylene donor and optical-switchable merocyanine acceptor for lead ion (Pb2+) detection in semi-aqueous media

A novel aggregation-induced emission (AIE) structure containing a tetraphenylethene (TPE) unit covalently linked with a spiropyran (SP) unit was synthesized and investigated in semi-aqueous solutions with 90% water fraction. The open-form structure of red-emissive merocyanine (MC) unit combined with TPE unit was utilized as a bi-fluorophoric sensor to detect lead(II) ion, which could be transformed from the close-form structure of non-emissive SP unit upon UV exposure. Moreover, the TPE unit as an energy donor with the blue-green photoluminescence (PL) emission at 480 nm was combined with the MC unit as an energy acceptor with the red PL emission at 635 nm. Due to the Förster resonance energy transfer (FRET) processes, the bi-fluorophoric sensor produced more efficient ratiometric PL behavior to induce a stronger red PL emission than that of the mono-fluorophoric MC unit. Hence, the PL sensor responses of the AIE bi-fluorophoric structure toward lead(II) ion could be further amplified via the FRET-OFF processes to turn off red PL emission of the coordinated MC acceptor and to recover blue-green PL emission of the TPE donor. Accordingly, the best LOD value for the AIE sensor detection toward Pb2+ was 0.27 μM. The highest red MC emission with the optimum FRET process of AIE sensor could be utilized in cell viability tests to prove the non-toxic and remarkable bio-marker of AIE sensor to detect lead(II) ion in live cells. The developed FRET-OFF processes with ratiometric PL behavior of the bi-fluorophoric AIE sensor can be utilized for future chemo- and bio-sensor applications.

Efficient FRET Approaches toward Copper(II) and Cyanide Detections via Host-Guest Interactions of Photo-Switchable [2]Pseudo-Rotaxane Polymers Containing Naphthalimide and Merocyanine Moieties.

A supramolecular [2]pseudo-rotaxane containing a naphthalimide-based pillararene host and a spiropyran-based imidazole guest was synthesized and investigated in a semiaqueous solution with 90% water fraction. Upon UV exposure, the close-form structure of nonemissive spiropyran guest could be transformed into the open-form structure of red-emissive merocyanine guest reversibly, which was utilized as a monofluorophoric sensor to detect copper(II) and cyanide ions. Moreover, the naphthalimide host as an energy donor with green photoluminescence (PL) emission at 505 nm was complexed with the merocyanine guest as an energy acceptor with red PL emission at 650 nm in 1:1 molar ratio to generate a [2]pseudo-rotaxane polymer, which was further verified by the diffusion coefficients of DOSY nuclear magnetic resonance (NMR) measurements. Due to the Förster resonance energy transfer (FRET) processes, the bifluorophoric [2]pseudo-rotaxane produced more efficient ratiometric PL behavior to induce a stronger red PL emission than that of the monofluorophoric guest; therefore, the PL sensor responses of the supramolecular [2]pseudo-rotaxane toward copper(II) and cyanide ions could be further amplified via the FRET-OFF processes to turn off red PL emission of the reacted merocyanine acceptor and to recover green PL emission of the naphthalimide donor. Accordingly, the best and prominent values of the limit of detection (LOD) for the host-guest detections toward Cu2+ and CN- were 0.53 and 1.34 μM, respectively. The highest red MC emission with the optimum FRET processes of [2]pseudo-rotaxane was maintained around room temperature (20-40 °C) in wide pH conditions (pH = 3-13), which can be utilized in the cell viability tests to prove the nontoxic and remarkable biomarker of [2]pseudo-rotaxane to detect Cu2+ and CN- in living cells. The developed FRET-OFF processes with ratiometric PL behavior of the bifluorophoric supramolecular [2]pseudo-rotaxane polymer will open a new avenue to the future applications of chemo- and biosensors.

Crystal structure and photophysical properties of a novel polyoxomolybdate porphyrin.

A novel polyoxomolybdate with a diprotonated porphyrin as counter-cation, namely, 5,10,15,20-tetrakis(4-carboxyphenyl)-21H,22H,23H,24H-porphine(2+) hexamolybdate(VI) pentahydrate, (C48H32N4O8)[Mo6O19]·5H2O or (H2TCPP)[Mo6O19]·5H2O, I, was prepared via the hydrothermal reaction of MoCl5, 5,10,15,20-tetrakis(4-carboxyphenyl)-21H,23H-porphine (TCPP) and distilled water. The crystal structure of hydrated polyoxometalate (POM) salt I was characterized by single-crystal X-ray diffraction. The compound is characterized by an isolated (zero-dimensional, 0D) structure, because it cannot extend via covalent bonds. The structure contains one [Mo6O19]2- anion, one (H2TCPP)2+ cation and five lattice water molecules. Each of the Mo6+ ions is six-coordinated and displays a distorted octahedral motif. The (H2TCPP)2+ cation displays a distorted saddle motif. A three-dimensional (3D) supramolecular framework is formed via hydrogen-bonding interactions. The compound shows a red photoluminescence emission.

Synthesis and characterization of a novel Europium(III) complex with a one-dimensional chain-like structure

By means of a solvothermal reaction of isonicotinic acid and europium perchlorate, a novel europium(III) complex, i.e. catena-[tri(μ2-isonicotinato-O,O′)-(biaqua-europium(III))-(triperchlorate)-(monohydrate)], [Eu(HIA)3(H2O)2]n·3n(ClO4)·nH2O (1; HIA ​= ​isonicotinic acid), was obtained. The molecular structure of complex 1 was characterized by single-crystal X-ray crystallography. Complex 1 crystallized in the space group Pī of the triclinic system with a ​= ​9.5500(2), b ​= ​10.9680(3), c ​= ​15.1214(4) Å, α = 104.299(2)°, β = 91.532(2)°, γ = 111.310(2)°, V ​= ​1417.92(6) Å3, C18H21Cl3EuN3O21, Mr ​= ​873.69, Z ​= ​2, Dc ​= ​2.046 ​g/cm3, μ(MoKα) ​= ​2.595 ​mm−1 and F(000) ​= ​864. The europium(III)) ions are coordinated by eight oxygen atoms (of which six come from six HIA ligands and two come from two water molecules) and displays a EuO8 square antiprismatic geometry. The adjacent europium(III) ions are interlinked by four or two μ2-bridging HIA ligands to generate an infinite one-dimensional (1-D) –Eu–(HIA)4–Eu–(HIA)2–Eu–(HIA)4–Eu– chain running along the a axis. The chains are further connected by π···π stacking and hydrogen bonding interactions to yield a three-dimensional (3-D) supramolecular network. Complex 1 exhibits red photoluminescence emission bands at 593 ​nm, 617 ​nm and 699 ​nm, which are originated from the 5D0 → 7F1, 5D0 → 7F2 and 5D0 → 7F4 characteristic transitions of europium(III) ions. It has CIE chromaticity coordinates of (0.5742, 0.3275). A solid-state UV/Vis diffuse reflection spectrum shows that complex 1 has a band gap of 5.02 ​eV with a direct transition process.

Synthesis of Eco-Friendly High PL Lifespan Manganese-Doped CuInZnS/ZnS QDs for White LED Applications.

Environmentally friendly and long PL lifespan Mn-doped CuInZnS (Mn:CIZS) and CuInZnS/ZnS (Mn:CIZS/ZnS) QDs, with respective red and yellow emissions, were synthesized using nontoxic precursors via a facile dual-step process based on the one-pot method. The resulting Mn:CIZS and Mn:CIZS/ZnS QDs exhibited confirmed strong red and yellow photoluminescence emissions at approximately 654 nm and 580 nm, respectively. The measured PL decay lifespan for the Mn: CIZS QDs is 2.52 μs due to well-organized surface passivation through the ZnS shell; the average PL lifespan for the Mn:CIZS/ZnS QDs is extended to 6.28 μs. Moreover, the WLEDs were composed of the Mn:CIZS/ZnS QDs. The resulting WLEDs offered admirable optical attributes, such as an excellent Ra of 89, a low Tc of 5075 K and radiant white light emanation at 60 mA functional current. Therefore, the outputs highlight the Mn:CIZS/ZnS QDs as hopeful cadmium-free resources for the interest of optoelectronics exploration.