An objective of the solar industry is to improve the efficiency of the light -electricity conversion process of photovoltaic solar cells. An alternative to achieve this purpose is to manage the solar spectrum that is absorbed by the solar cell in order to match it with the solar cell responsivity. It can be done, for example through the downconversion process, covering the solar cell with photonic

Three basic borate glasses were prepared from the systems (BaO–B2O3), (SrO–B2O3) and (Bi2O3–B2O3) together with samples doped with 0.25% CuO from the three systems. Collective characterizations of the optical, FTIR, photoluminescence spectra of the prepared glasses were carried out before and after impinging to gamma irradiation. The results were analysed in relation with the structural building groups

A red luminescent YxAl6-xSi2O13:Eu,Bi nanophosphor was successfully synthesized by a rapid, energy-saving microwave-assisted synthesis. This method significantly reduced synthetic time and energy consumption over previous reports using traditional solid-state methods. The results revealed that the single phase of Al6Si2O13 (mullite) nanocrystals had spherical shapes of 30–60 nm diameters. In addition

The 2.0 μm spectral characteristics of the 980 nm LD pumped Er3+/Ho3+/Yb3+ tri-doped Na5Y9F32 single crystals grown by an improved Bridgman method were investigated with the help of their absorption spectra, emission spectra and decay curves. The introduction of Yb3+ and Er3+ greatly improves the 2.0 fluorescence intensity through joint energy transfer processes from Yb3+ to Er3+, and Er3+ to Ho3+

We report on the synthesis and photoluminescent performance of the Ba2+ ions doped Eu(HCOO)3 phosphors as well as their promising applications in indoor illumination. The thermal stability of the synthesized sample with microparticles was characterized by the thermogravimetric analysis. Irradiated by 396 nm, the unique emissions of Eu3+ ions originating from the 5D0 → 7FJ (J = 1, 2, 3, 4) transitions

We report time-resolved second-order fluorescence between Stark levels of 1D2 and 3H4 in Pr3+:YPO4 nanocrystals with different crystal phase. Both maximum emission wavelength and fluorescence lifetimes are modulated by phase composition and dressing effect. We have found that the maximum emission wavelength shifts from yellow to orange-red region with continuous phase transformation from hexagonal

Inorganic upconverting nanoparticles that can be excited with 808 nm laser radiation are gaining much attention recently. Living tissues, as well as water do not heat up as intensively when embedded upconverting nanoparticles are excited under such wavelength if compared to commonly used 980 nm laser radiation for excitation. To this end, a series of NaGd0.995-xYbxNd0.005F4 nanoparticles were synthesized

In this paper, we report a simple one-pot strategy to synthesize highly stable SiO2-coated orange-yellow CsPb0.7Mn0.3Br0.75Cl2.25 quantum dots with strong orange-yellow photoluminescence. The microstructure characterization indicates that the CsPb0.7Mn0.3Br0.75Cl2.25 quantum dots were effectively encapsulated by the SiO2. The SiO2-coated CsPb0.7Mn0.3Br0.75Cl2.25 quantum dots show higher humidity stability

Germanium silicate suboxide films deposited from GeO/SiO and GeO/SiO2 precursors onto Si(001) substrates using evaporation in high vacuum were modified by swift heavy ions. The films were irradiated by 167 MeV Xe+26 ions with fluences varying from 1011 to 1013 cm−2. We report photoluminescence in the infrared range both at low and at room temperature, which is most probably due to defect-induced radiative

An effort was made to get an idea regarding the correlation between structure and radiative properties of Gd incorporated LiBaB9O15 matrix. The samples were synthesized via a combustion route and characterized using X-ray diffraction (XRD). Up to 0.06 mol of the doping, no phase segregation was observed in the samples. Photoluminescence (PL) experiments were carried out in order to understand the radiative

Undoped and Eu-doped CaZrO3 crystals were synthesized by the xenon lamp floating zone method, and photoluminescence (PL) and scintillation properties were investigated. The undoped CaZrO3 exhibited a broad PL spectrum peaking at around 410 nm while the Eu-doped CaZrO3 showed some sharp emission lines due to 4f-4f transition of Eu3+. The PL decay time constant of the undoped CaZrO3 was 77.8 ns while

Cancer could seriously threaten people's health, even life. Rare earth upconversion nanoparticles (UCNPs) that emit higher energy UV/visible light when excited by low energy NIR light have aroused considerable attention in biomedical fields, which stems from their unique optical and chemical properties including the low spontaneous fluorescence, high signal-to-noise ratio, tunable emission, low toxicity

Sensitization of Eu3+ with Ce3+ suffers from low emission intensities due to the well-known metal-to-metal charge transfer (MMCT), which effectively quenches the luminescence process. By separating sensitizer and activator spatially, reduced MMCT quenching and thus higher luminescence intensities can be expected. We chose TbF3 as host material, since it is well-known that Tb3+ acts as a mediator in

In order to overcome the shortcomings of insufficient red light component and poor thermal stability of commercial white light emitting diode (WLED), YAG:Ce, R (R: Gd3+, Pr3+, Gd3+ and Pr3+) fluorescent thin films were prepared by pulse laser deposition (PLD). The composition and microstructure, photoluminescence properties, and red-enhanced mechanism of co-doped YAG fluorescent thin films, as well

In this work we present for the first time the effective modulation of spectroscopic parameters of Ni2+ emission based luminescence nanothermometer (LNT). Emission of Ni2+ ions, highly susceptible to the local symmetry variations, can be easily modulated by the change of the crystal field strength of matrix. In this approach we proposed four ATiO3 perovskite nanocrystalline matrixes, namely SrTiO3

The development of the multi-functional glass-ceramic based luminescent materials remains challenging. In this perception, the effects of silver (Ag) nanoparticles (NPs) sensitization on the spectroscopic characteristics of the holmium ions (Ho3+) activated zinc-sulfo-boro-phosphate glass-ceramics (GCs) were evaluated. These GCs were prepared by the standard melt-quenching and thoroughly characterised

Eu3+-activated Ca3Mo0.2W0.8O6 phosphors, which presented bright red emissions mainly from the 5D0 → 7F2 transition of Eu3+ ions upon the near-ultraviolet and blue light excitation, were successfully prepared by a traditional high-temperature technology. The crystal structure, phase constitution, morphology, electronic structure, photoluminescent behaviors, decay time, internal quantum efficiency and

In this work, intense blue up-conversion (UC) luminescence in LaNbO4: Tm3+/Yb3+/Nd3+ phosphors were obtained under the excitation of 808 nm. The laser-induced thermal effect and the role of Nd3+ in this type of phosphors were discussed. Compared with Tm3+ singly doped and Tm3+/Yb3+ doubly doped samples, thousands-fold and 30-fold overall enhancement in the blue emission intensity of Tm3+ in Tm3+/Yb3+/Nd3+

Temperature dependences of photoluminescence (PL) spectra of two different InGaN/GaN multiple quantum wells (MQWs) were studied at different excitation powers. The results show that, compared with MQWs with a gradually increased In content, the MQWs with a gradually decreased In content showed a lower peak energy, stronger phase separation, more robust carrier localization effect, and a stronger quantum-confined

Luminescent poly p-phenylene vinylene (PPV) thin films were produced by the layer-by-layer technique, using organic dyes as the counter ion. It was observed that, when dyes with azo groups are incorporated in the PPV polymeric chains, the fluorescence intensity can be substantially increased by the photo-irradiation of the film with a linearly polarized laser beam. The data show that such emission

The luminescence properties of the Mn4+ and Cr3+-activated fluoride and oxide phosphors have been discussed in detail. The Mn4+ and Cr3+-activated fluoride and oxide phosphors can be classified into five types from an aspect of the different luminescence properties: F–Mn, F–Cr, O–Mn, O–Cr-A, and O–Cr–B. The representative phosphors considered here are: BaSiF6:Mn4+ (type F–Mn), K2NaScF6:Cr3+ (type F–Cr)

Due to the shielding effect of the outermost electronic layer 5s and 5p of rare earth, the near-infrared photoluminescence (PL) of Er3+ can not be easily affected by the external environment. However, we have regulated the near-infrared PL of Er3+ by changing temperature, which is ascribed to the phase transition of BaTiO3 from tetragonal to cubic phase and the presence of impurity. It also found that

The optical spectroscopy of Bi3+ in d10-based post transition metal oxides (i. e. gallates, germanates, antimonates indates, stannates) is reviewed and analyzed in the frame of empirical models. 20 different compounds are examined. From this, a methodology is introduced to identify the preferred doping sites for Bi3+ and predict the intra- or extra-ionic origin of the Bi3+ emission in these systems

Alpha irradiation is less efficient in inducing the thermoluminescence (TL) signal compared to beta and gamma irradiation. Although TL dating has been applied to calcite from various geological contexts, studies of the alpha effectiveness (a-values) of calcite are relatively scarce, and the reported a-values are focused on the 280 °C TL peak of speleothem calcite. In this study, three single-aliquot

The optical properties of InP/InGaP quantum structures (QSs) grown using migration-enhanced molecular beam epitaxy at growth temperatures ranging from 440 to 520 °C were investigated using temperature-dependent photoluminescence (PL) and time-resolved PL spectroscopy. As the growth temperature increased from 440 to 520 °C, the PL peak energies originating from quantum dots and quantum dashes were blue-shifted

In order to estimate the characteristics of delayed luminescence (DL) decay curves obtained from green algae (Raphidocelis subcapitata), principal component analysis (PCA) and hierarchical cluster analysis (HCA) were performed on decay curves of 26 samples exposed to photosynthetic inhibitors (DCMU, DBMIB, Ant-A, CCCP) having different action mechanisms. PCA characterized the decay curves, which are

Metal-selenide nanostructures from different semiconductor families such as ZnSe, SnSe, and CuxSey were synthesized with different Se/cation ratios. The effects of non-stoichiometric defects such as vacancies and interstitials on their optical properties were investigated. X-ray diffraction patterns (XRD) indicated that the Se/Zn > 1 and Se/Cu > 1 conditions led to creating heterostructures of ZnSe/Se

Series of Tb3+-doped whitlockite-type phosphates Ca9–xZnxTb(PO4)7 and Ca9–xZnxLa0.99(PO4)7:0.01 Tb3+ were synthesized using a standard high temperature route. The luminescence properties of these compounds were determined by the photoluminescence emission (PL), the excitation (PLE) spectra and lifetime measurements. A green-emitting LED device was fabricated using the most effective one. No concentration

Recombination luminescence (RL) and RL-detected electron paramagnetic resonance (RL-EPR) in BaY2F8 single crystal has been investigated after irradiation with X-rays at low temperature. The recombination process, which lasts for several hours at 4 K, results in several broad bands in the RL spectrum. RL-EPR spectra show pronounced angular dependences on crystal orientation relative to external magnetic

The three-dimensional coordination polymer [Eu (ptc).3H2O]n has been synthesized under hydrothermal conditions and characterized by powder X-ray, infrared, and thermogravimetric analyses. The compound crystallizes with cell parameters a = 12.127, b = 7.409, and c = 13.672 and cell volume = 1220.77 Å. This article presents an experimental and theoretical study to elucidate the structure of IR-LOFs by

Temporally stochastic, abrupt photoluminescence (PL) intermittency (blinking) has been long recognized to be characteristic of single quantum-emitters as intensity fluctuations average out over the ensemble. While there are a few rare examples of PL blinking in spatially extended (∼μm) yet quantum-confined (1 or 2-D) nanostructures, such phenomenon is in general spatiotemporally uncorrelated. However

Epitaxial growth of III-V heterostructures on non-native substrates such as Silicon (Si) or Germanium (Ge) is one of the promising research topics for the last two decades. The interface between polar III-V semiconductors and non-polar substrates (Si or Ge) plays a crucial role in monolithic integration. However, there is an anticipation of epitaxial GaAs growth on Ge substrate because of the lower

Non-contact thermometry operating at the sub-micrometer level based on self-referencing upconversion (UC) micro-nanomaterial is an attractive pursuit for optical thermometers. Here, a novel accordion-like Y2O3:Er3+ nanothermometer with green/red UC luminescence is obtained from the solvent-free grinding and the following temperature-programmed calcination of the Er3+-doped Y-containing metal-organic

Excited state intramolecular proton transfer (ESIPT) and twisted intramolecular charge transfer (TICT) play fundamental roles during the excited state dynamics of dyes and fluorescent sensors. In this contribution, the ESIPT process is demonstrated to trigger the TICT process during the photo-physical process of a turn-on Al3+ sensor. The non-emissive TICT state can be facilely reached after the photo

Presented are the results of comparative study of the decay kinetics for luminescence in the visible (350 ÷ 700 nm) and infrared (1000 ÷ 1900 nm) spectral regions, which is excited in CsI:Tl crystals by a pulsed electron beam (Еm = 250 keV, t1/2 = 15 ns, W = 8 mJ/cm2). The infrared luminescence is assumed to be caused by radiative transition from the excited 62P3/2 state into the ground 62P1/2 state

A single crystal of TlAlF4 is grown by a self-seeded vertical Bridgman-method. The measured powder X-ray diffraction pattern is compared with the standard JCPDS pattern and found to be in good agreement. The crystal structure and cell parameters are calculated and refined by Rietveld refinement analysis. The optical absorption spectrum is measured and the characteristic spectral properties of Tl+ bands

Herein we report the synthesis and investigations of the new lanthanide coordination compounds [LnL3bipy] (Ln1) and [LnL3phen] (Ln2) with carbacylamidophosphate type ligand diphenyl-N-benzoylamidophosphate (HL = [C6H5CONHPO(OPh2)2]) and additional ligands 2,2′-bipyridine and 1,10-phenantroline. The obtained complexes were characterized by means of X-Ray, thermal gravimetric analysis, IR, 1H NMR, UV

The terahertz (THz) absorption spectra of purine and its derivative, uric acid, have been measured by using terahertz time-domain spectroscopy (THz-TDS) system in the frequency range from 0.3 to 1.6 THz. In parallel with the experimental study, the mechanism of the THz characteristic absorption peaks and the weak interaction type of purine and uric acid were investigated by density functional theory

The effects of ultraviolet (UV) radiation exposure on the thermoluminescence (TL) of aluminium oxide co-doped with carbon and magnesium (Al2O3:C,Mg) are reported. An Al2O3:C,Mg single crystal was investigated as a potential UV TL dosimeter after exposure to a Hg lamp radiation. The TL peak intensity and area under the curve signals were investigated as a function of the UV exposure time. Intense TL

To explore a new color-adjustable self-emitting in SrGa2Ge2O8:Eu phosphors, a series of experiments and characterization were carried out in this paper. Through a classic solid state method, we successfully synthesized the SrGa2-yGe2-zO8:xEu (0 ? x, y, z ≦ 0.2) phosphors. The resulting SrGa2-yGe2-zO8:xEu (0 ? x, y, z ≦ 0.2) phosphors had been structurally characterized by X-ray Powder Diffraction Refinements

Metal halide perovskites have aroused extensive attention due to their excellent photoelectric properties. But the toxicity and instability of lead-based perovskite restrict their development severely. Recently, lead-free Cu-based perovskites have emerged as promising environmental friendly photoelectric materials on account of their low toxicity and equally excellent properties. Here, we report the

Na2ZnP2O7: x mol. % Eu3+ phosphors with different dopant concentrations (x = 1, 2, 4, 6, 8) have been synthesized via high-temperature solid-state reaction. X-ray diffraction, scanning electron microscopy analyses and infrared (IR) spectroscopy were applied for detailed structural characterization. Under 393 nm excitation, the photoluminescence spectra displayed the 5D0 → 7FJ (J = 1, 2, 3, 4) intra-4f

Er3+ and Yb3+ codoped MoS2 powders have been fabricated by hydrothermal synthesis. The impact of Er3+ and Yb3+ codoping on the structure, morphology, energy band structure and upconversion photoluminescence properties of samples have been studied by XRD, SEM, TEM, XPS and UPL. XRD results reveal that the crystal structure of samples is well matched with the 2H–MoS2, and the crystallinity of MoS2–Er:Yb

A series of BaY2(MoO4)4:Eu3+,Tb3+ phosphors were synthesized by solid state reaction. The phase purity, crystal structure and photoluminescence properties were identified by X-ray diffraction, SEM, DRS, excitation and emission spectra, and luminescence decay curves. The emission color can be tuned from green to yellow and then to red by changing the concentration ratio of Eu3+ and Tb3+ under near-UV

Here in, we report the mechanoluminescence (ML)from sugar crystals measured with different techniques. In case of statical ML, many ML pulses originate from sugar crystals andthe total number of ML pulses increases linearly with increasing applied load. However, in case of impulsive excitation technique, the ML intensity increases linearly with increasing time, attains a saturation value and finally