Down conversion of solar UV and blue light is one of the few ways of surpassing the Shockley-Queisser limit of solar cells. One of the most efficient down conversion systems is the Pr3+ - Yb3+ lanthanide pair. However, these ions do not provide any strong absorption for solar UV and blue light, thus require sensitizing. In this work, we report self-sensitization by inducing strong Laporte allowed f

This research dealt with the investigation of luminescence properties of undoped and La doped Lu3Al5O12 single crystals using synchrotron radiation excitation. The influence of La3+ doping on the exciton emission and decay kinetics properties of Lu3Al5O12 single crystals was studied at 7 K and room temperature. Undoped and La3+ doped samples showed bright luminescence in the UV spectral range. In undoped

This work deals with the spectroscopic properties of praseodymium doped single crystalline lutetium aluminum garnet (LuAG:Pr3+). A special focus was set on temperature- and time-dependent spectroscopy. Beyond the well-known down-conversion luminescence of LuAG:Pr3+, also UV-A/B up-conversion luminescence under excitation with a 488 nm laser was thoroughly investigated. Furthermore, the results of the

Earlier, it was shown by the EPR method that at a very low concentration of the Nd3+ ion in the Nd3+:CaF2 crystal, highly symmetric cubic centers with the Oh symmetry are formed. In the present study, the optical centers of the Nd3+ ion with an anomalously long radiative lifetime τR = 13.6 ms of the 4F3/2(1) crystal-field (CF) level in the Nd3+ (0.05 at.%): Na+ (0.2 at.%): CaF2 single crystal at T = 7 K

Transparent glass-ceramics (GCs) based on Co2+-doped γ-GaxAl2−xO3 spinel nanocrystals were developed in the lithium aluminogallosilicate glass system with TiO2 as a nucleating agent. The initial glass contains spinel nanocrystals with sizes less than 3 nm. Secondary heat-treatments in the temperature range of 680–800 °C result in fabrication of transparent GCs based on γ-GaxAl2−xO3 crystals enriched

Materials with long persistent luminescence (PersL) have caused widespread interest among scientists and industry for decades. Currently, there is widely available information on the long persistent luminescence materials with emission in the blue and green spectral range, while the number of publications on the afterglow in the red and near-infrared spectral range is considerably lower. In the course

Multifunctional Pr3+:YPO4 single crystals were investigated by high-resolution optical Fourier spectroscopy. The analysis of the transmission and luminescence spectra allowed us to supplement information on crystal-field levels of the Pr3+ ion. Shapes of spectral lines corresponding to transitions from the ground state to the degenerated Γ5 crystal-field levels reveal the hyperfine structure and unambiguously

Erbium doped Si-related compound films, with the 1540 nm emission coinciding with the minimum loss window of optical telecommunication, are regarded as appealing platforms of light sources for silicon photonics. In many previous reports, however, the unipolar carrier injection in silicon oxide/nitride films leads to favorable impact excitation of Er rather than sensitization, requiring high onset voltage

Recently, the active controlled broadband terahertz(THz) emitter from semiconductor crystal has attracted considerable attention due to its field intensity tuning properties, which makes it a promising candidate for wide applications in THz photonics. A broadband THz wave radiation intensity by applying electric field control in an n-type semiconductor tin selenide (SnSe2) crystal had been reported

Cancer has become the leading cause of death for its high incidence and mortality. Early diagnosis and treatment are essential for the inhibition of tumor growth. In this work, A biocompatible, nontoxic, near-infrared fluorescent tumor targeting nanoparticle KHLF(K5HoLi2F10) was prepared by a delicate method for the early diagnosis of tumor. The surface functionalization of the nanoparticle endows

The well-known thermoluminescent material LiF:Mg,Cu,P (MCP) was previously shown to emit significant optically stimulated luminescence (OSL). In this paper, we investigate the rate of OSL recombination processes in MCP, expressed as effective lifetimes, using time-correlated single photon counting, in this context often referred to as time-resolved pulsed OSL. The recombination luminescence fell into

In this work, we presented a theoretical investigation of single-triplet excited state transition process by the energy gap (ΔEST) and spin-orbit coupling (SOC) for a series of novel designed anthraquinone compounds in solution. The molecular conformation, steady-state spectra and molecular orbitals were performed by quantum chemistry calculations to investigate the substituent effects on the ΔEST

The processes of creation of luminescence centers by laser radiation in transparent anisotropic crystals are investigated using MgF2 as an example. To monitor the concentration of the created centers, a luminescent method was developed, which ensured a direct proportionality between the luminescence intensity and the concentration of centers. By the joint action of coherent pairs of femtosecond laser

We demonstrate a new way to manipulate and to control the RGB chromaticity of the luminescence of Ln-based metal-organic frameworks with MOF-76 structure. This new way is based on preliminary UV photostimulation. Particularly, we reveal that besides the conventional ways to control luminescence chromaticity based on alteration of chemical composition and excitation wavelengths, the chromaticity of

In our work, the stable Q-switched-mode-locked (QML) operations were generated in Er-doped fiber laser based on dispersion compensating fiber (DCF) saturable absorber (SA) for the first time. Firstly, the dissipative soliton mode-locked operation was achieved in fiber laser without DCF. After that, the DCFs with different lengths were separately added into fiber laser to gradually optimize the cavity

The prepared Ti:MgAl2O4 crystal samples were annealed at different temperature for 24 h in an air atmosphere, and then the transmission spectra, emission spectra, excitation spectra and photoluminescence decay curve were recorded. Furthermore, electron spin resonance of annealed samples were measured at 130 K. It is found that the absorption bands disappeared and the fluorescence intensity increased

Judd-Ofelt theoretical approach and Rietveld refinement technique are implemented to gain a profound insight of remarkable structural and optoelectronic aspects of Eu3+-doped Ca9Bi(VO4)7 nanophosphor. The bright red emitting vanadate-based series was developed via an efficient route of solution combustion synthesis (SCS). The Rietveld refinement, been employed upon powder X-ray diffraction (PXRD) patterns

As important members of biothiol species, cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) are involved in numerous physiological activities. Moreover, abnormal levels of these biothiols are closely relevant to a series of diseases. Therefore, it's of great importance and challenges to develop efficient approaches for sensitively detecting biothiols. Herein, a novel fluorescent probe JSC-RSH

We demonstrate a sub-nanosecond, high peak power Yb:YAG/Cr4+:YAG/YVO4 passively Q-switched Raman micro-laser (PQSRML) operating at 1134 nm. The effect of transmission of the output coupler (TOC) and Cr4+:YAG initial transmission (T0) on the Raman laser performance have been investigated. Stable Raman laser pulse trains have been observed for Yb:YAG/Cr4+:YAG/YVO4 PQSRMLs with different combinations

Green-emitting, apatite structure of Ca4-yLa6(AlO4)x(SiO4)6-xO1-x/2: yEu2+ was synthesized by using the high-temperature solid-state method under reducing atmosphere (90%N2-10%H2). Corresponding to the Eu2+ of 4f65d1→4f7 transition at the excitation wavelength of 335 nm, a broadband emission of 450-700 nm showed. Eu2+ lattice selection in Ca4-yLa6(AlO4)x(SiO4)6-xO1-x/2: yEu2+ phosphor were discussed

A Tm,Ho:LuYO3 crystal was grown using the optical floating zone method. The XRD pattern shows that it belongs to the cubic crystal system (Ia‾3 space group). The absorption cross-section at 796 nm is 3.45 × 10−21 cm2, where the full width at half maximum (FWHM) is 45 nm. The emission cross-section at 2080 nm is approximately 1.33 × 10−20 cm2. The broad fluorescence band extends to 2200 nm where almost

A method is presented for analyzing complex thermoluminescence (TL) glow curves from disordered materials using aluminosilicate glass as an example. The method is first described using simulated TL glow curves, firstly by assuming a Gaussian distribution of trap depths Et and a fixed frequency factor s, and secondly by assuming distributions of both Et and s. The method is able to reproduce the input

Various Cr3+-activated oxide phosphors can be classified into two groups: a strong crystal field group [E(2Eg)ZPL < E(4T2g)ZPL] and a weak crystal field group [E(2Eg)ZPL > E(4T2g)ZPL] from an equality relation of the zero-phonon line (ZPL) energies of 2Eg and 4T2g. Obtaining reliable Racah parameters for the 3d3 ion (Cr3+) usually needs accurate information on the three excited-state ZPL energies,

We report on laser site-selective spectroscopy, as well as high resolution, infrared to optical absorption, of both the six and seven -fold coordinated, C1 symmetry sites for Nd3+ doped Y2SiO5. A total of fifty three crystal-field energy levels have been determined for both sites. We also present the temperature dependencies of the spectral linewidth and line position as measured in absorption. The

We report a detailed analysis of both structural characterization and high-resolution spectroscopic properties of Nd3+-doped YPO4 and LuPO4 in the form of nano/micro powders. LuPO4, like YPO4 crystalizes in a zircon-type tetragonal system. Nd3+ ion in substitution of Lu3+ or Y3+ cations occupies the main symmetry site D2d and the presence of additional components in the spectra may indicate the presence

Materials with tunable photoluminescence (PL) are highly desirable. It can lead to important applications such as photodetectors, bio-imaging, and broadband modulators. In this work, nitrogen-doped graphene oxide quantum dots (NGOQDs) were synthesized by hydrothermal method. The microstructures as well as optical properties of NGOQDs were studied. The as-prepared NGOQDs present tunable PL and exhibit

Theoretical calculations of the local structures and the electron paramagnetic resonance (EPR) parameters for the impurities VO2+ and Cu2+ centers in oxyfluoroborate glasses (OFG) were performed by using the perturbation formulas of the EPR parameters for tetragonally compressed octahedral [VO6]8- and tetragonally elongated octahedral [CuO6]10− clusters, respectively. In the calculations, the required

We report the phototransferred thermoluminescence of tanzanite induced by 470 nm blue light. A glow curve measured after irradiation to 120 Gy and heating at 1 °C s−1 shows three nominal peaks at 86 °C (peak I) and two secondary peaks at 160 °C and 320 °C. The latter two peaks are collocated peaks with each one consisting of multiple components. Phototransferred thermoluminescence is only reproduced

A series of Bi3+ ion doped Ln2O3 (Ln = Lu, Gd, La) phosphors have been prepared through a simple urea-based precipitation method. The 1S0 → 3P1 transition position shift of Bi3+ ion has been investigated in Bi3+-doped Ln2O3 phosphors. This is caused by difference of covalency and coordination number. The 1S0 → 3P1 transition of Bi3+ ion in Gd2O3 crystal shifts to lower energy position than that in

CsPbBr3 perovskite quantum dots (PQDs) have drawn much attention for their high photoluminescence quantum yield and great potential in optoelectronic applications. However, they suffer from poor stability under humid condition. This paper reports CsPbBr3 PQDs incorporated in aluminum stearate (AlSt3) matrix via an improved co-precipitation approach, in which AlSt3 not only acted as hydrophobic matrix

A new zinc(II) coordination polymer (Zn-CP) constructed from 4,4-dipyridyldiphenyl ether (BPDPE) and 1,2-benzenedicarboxylic acid (1,2-bdc), namely [Zn2(1,2-bdc)2(BPDPE)2]n (1), has been discovered using the solvothermal method. Complex 1 is a two-dimensional sheet with uncoordinated pyridine group composed of one-dimensional chain [Zn(1,2-bdc)]n connected by BPDPE, and finally forms a three-dimensional

Scintillation mechanisms and performance parameters of quaternary (Gd,Y)3Al2Ga3O12 compositionally disordered polycrystalline garnet type ceramics doped with Ce or Tb have been investigated for the first time. Similar light yield dependence on a Gd content in the composition was evidenced for both dopants. The highest light yield achieved in Tb doped samples was found to be four times higher than in

Temperature-dependent luminescent properties of dual-wavelength blue-cyan light emitting diodes (LEDs) based on InGaN quantum wells were investigated by means of photo- (PL) and electroluminescence (EL) spectroscopy techniques. The results showed that the thickness of the interwell GaN layer had a great impact on the spectra (especially on the EL ones) at room temperature. At low temperatures, however

Hexagonal boron nitride (h-BN) crystal powders were characterized for structural and optical properties. Deep UV photoluminescence (PL) spectroscopy was employed for the optical characterization. We studied the effect of annealing on the PL emissions from the h-BN crystal powders. We observed sharp atomic-like PL emission lines in the UV spectral region at 4.10 and 4.12 eV along with their longitudinal

Nowadays, ultraviolet light emitting diodes (UVLEDs) have aroused great interest in past few years for their promising application in adhesive curing, security identification and solid-state lighting etc. In gallium nitride (GaN) based LEDs, the patterned substrates and vertical devices' structure both played pivotal roles in elevating devices' performance. In this work, vertical near-UV-LEDs (405 nm)

Fluorescent nanodiamonds (NDs) are hard, nontoxic, have high melting point and possess physical and chemical stability. In this paper, the NDs with nitrogen vacancy (NV) centres have been studied with steady-state and time-resolved photoluminescence spectroscopy. The broad fluorescence spectrum spans in the visible-near IR region (from 500 nm to 900 nm) with presence of prominent characteristic peaks

Device performance enhancement in quantum dot light-emitting diodes (QLEDs) is realized by adding a small amount of insulating polymer polymethyl methacrylate (PMMA) into the emitting quantum dot layer. Pool-Frenkel effect is observed through temperature-dependent current density-voltage experiments, indicating the important role of trap states, and the addition of the insulating PMMA helps to reduce

We demonstrate here a novel reaction-based chemodosimeter 2-[(4′-triphenylvinyl-biphenyl-4-ylimino)-methyl]-phenol (TPE-SA) for effective UO22+ recognition. TPE-SA responds to UO22+ with dramatical fluorescence enhancement and blue-shift, readily perceived even by the naked eye. Specifically, the fluorescence intensity at 500 nm is linearly correlated with the concentration of UO22+ ranging from 2

Metal halide perovskite nanocrystals (NCs) have sparked considerable attentions in the area of light-emitting diodes (LED) by virtue of their remarkable color purity and spectral tunability (400–700 nm). However, the optoelectronic performance of LED devices based on perovskite NCs is severely limited by the problem of charge injection since (i) the charge injection layers exhibit significant differences

In this study, the thermoluminescence characteristics of CaF2:Mn chips exposed to environmental-like doses are examined. Thermoluminescence measurements, at different doses (0.04–7.2 mGy) and heating rates (1–25 °C/s), were carried out. The sample's glow curves were analyzed using glow curve deconvolution (GCD), whole glow peak (WGP) and initial rise (IR) methods. The glow curves of the chips, readout