Due to high transmittance, excellent chemical stability, ease of machining, and other advantages, silicon-based oxide glass is considered to be an ideal matrix material. By introducing different lighting dopants, the optical glass with different properties has been widely used in many fields. However, the preparation technologies of the optical glass are facing new challenges because of these volatile and unstable lighting dopants which easy to be decomposed. This review introduces the development status and the preparation techniques of the silicon-based light-emitting glass containing bismuth ions, quantum dots and phosphors. By comparing the melting method, Sol-Gel, solid-state sintering and spark plasma sintering (SPS), the research progress and superiority of SPS technology applied in optical glass preparation are focused on and the developments of this new preparation technology are also reviewed.

Upconversion nanoparticles (UCNPs) have made a significant and valuable contribution to photophysics and biomedicine, due to their specific spectroscopic characteristics. However, the ensemble spectroscopy of UCNPs is limited for the electronic behavior in average effect, which ignores the fact that the nanoparticles are heterogeneous. Towards the research focus on heterogeneous intrinsic structure, unique photophysical phenomena, and advanced applications, the optical characterization of single UCNPs are promoted to a frontier breakthrough of UCNPs community. Electronic behavior detection aimed at a single nanoparticle displays signals from the micro-structure of nanoparticles, while single nanoparticle spectroscopy offers clear insight into the interplay between intrinsic and extrinsic influences without noise, and subsequently gives instructions for the high quality preparation of UCNPs. Single nanoparticle optical characterization possesses a powerful capacity to explore the crystalline structure anisotropy related optical differences, or some unexpected unique optical phenomena at sub-micron and even nano-scale. In this review, the importance of single UCNPs characterization and single particle detection methods are overviewed, in which the considerable emphasis is placed on the specific spectroscopic study of single UCNPs Showing fantastic photophysical phenomena beyond ensemble measurement. Finally, this review identifies promising opportunities in which single UCNPs characterization technique can accelerate on-going research with a remarkable depth and breadth, facilitate discovery of upconversion nanoparticles that overcome fundamental limitations of current ensemble level.

The synchrotron radiation and free electron laser are electromagnetic radiation light sources which are both generated by the relativistic electron beam. Both sources have been widely used in the national economic, scientific and technical researches, national defense and military fields. The insert device made of permanent magnet is one of the key equipments of the synchrotron radiation light source and the free electron laser facility. Magnetic properties and quality of magnetic materials especially have significant influence on magnetic field quality, magnetic field peak value, magnetic field stability and operation scheme of insert devices. This paper reviewed characteristics of synchrotron radiation and free electron laser, and their conceptual application.

Noble metallic nanoparticles-glass composites have attracted much interest because of their technical potential as nonlinear media. In present work, the influences of ion-exchange and thermal treatment on the photoluminescence of noble metal doped silicate glasses were discussed based on photoluminescence (PL) spectroscopy and ligand field theory. The results indicate that metallic ion concentration in silicate glass increases with extending ion-exchanged period. There exist isolated Ag⁺ ions and Ag₂⁺ clusters in Ag-doped silicate glass. Concentration of the isolated Ag⁺ ions decreases quickly and Ag₃²⁺ clusters appear after annealing the Ag-doped silicate glass in H₂. While there exist only isolated Cu⁺ and Cu²⁺ ions in the Cu-doped silicate glass, no photoluminescence of Cu⁺ clusters are found in the glass. The existence of Cu²⁺ ions makes the luminescence of Cu⁺ quenching. It is very difficult to introduce Cu⁺ ions into the annealed Ag-doped glass in H₂ via Cu⁺ for Na⁺ ion-exchange.

Pr³⁺-activated 50SiO₂ -10AlF₃-5TiO₂-30BaF₂-4LaF₃ glass were synthesized by a conventional melting technique, and then annealed at 640℃, 660℃ and 690℃, respectively. Transparent Ba₂LaF₇: Pr³⁺ glass ceramics were successfully prepared and the transparency still remained at a high level. X-ray diffraction and transmission electron microscope were used to monitor the evolution and microstructural changes after the glass specimens were annealed at temperature increasing from 640℃ to 690℃. The spectral properties of glass and glass ceramics were also investigated. Results show that Ba₂LaF₇ nanocrystals were precipitated in the teat-treated glasses and the measured luminescent properties indicate that Pr³⁺ ions are gradually incorporated into the precipitated Ba₂LaF₇ crystalline phase. Under 443 nm excitation, the Commission Internationale de L’Eclairage (CIE) chromaticity coordinates for the glass ceramics heated at 660 ℃, were estimated to be (0.323, 0.343) and exactly located in the region of white light. Current findings reveal a fact that the prepared materials have potential as replacements of commonly employed phosphors applicating in white light-emitting diodes.

The Li⁺ and Zn²⁺ doped InP quantum dots (denoted as Li: InP QDs and Zn: InP QDs) were synthesized via an in-situ nucleation doping approach. Effects of dopant on the structure, size and optical property of QDs were investigated in detail. The results showed that Li: InP and Zn: InP QDs were well crystallized with uniform size. In the case of Li⁺ dopant, Li⁺ did not enter the InP lattice, but inhibited the nucleation and growth of InP QDs. Blue shifts were observed in UV-Vis absorption spectra and fluorescence spectra due to the quantum size effect of Li: InP QDs. Compared with Li⁺, Zn²⁺ dopant also inhibited nucleation and growth of InP QDs, but InP/Zn₃P₂/ZnO composite was produced with a core-shell structure, resulted in a great improvement of photoluminescence (PL) intensity. Especially when the doping concentration of Zn/In atomic ratio was 0.2, the PL intensity was increased more than 100 times as compared with that of undoped InP QDs. This work may provide a considerable approach to the synthesis of short-wavelength InP QDs.

Photonic crystal (PC) possesses long-scale periodicity and has been widely applied in modifying visible and near-infrared photonic band gap. One of the extraordinary properties of the PCs is the modulation on spontaneous emission of embedded luminescence centers. In this study, three-dimensional NaGd (WO₄)₂:Yb³⁺/Tm³⁺ inverse opal photonic crystals (IOPC) with highly oridered periodic structure were prepared by self-assembly method using PMMA as template. The modulation effect of PC on emission spectra and dynamics of Tm³⁺ ions were systemically studied. In NaGd (WO₄)₂:Yb³⁺/Tm³⁺ inverse opal photonic crystals, due to unique cavity structure and photonic band gap effect, the emission line of ¹G₄-³H₆ transition decreases by ~45% and the spontaneous radiation rate is suppressed by ~30%. Meanwhile, the up-conversion local thermal effect is largely suppressed. This experimental analysis indicates that the IOPC structure is an effective device for improving efficiency of up-conversion luminescence.

Perovskite-type organic-inorganic hybrids CH₃NH₃PbX₃(X= halogen) are good application materials for solid-state solar cell devices. To study the basic performances of these perovskite compounds, growth and optical-electrical properties of the large single crystals with high quality are of great necessity. In present study, CH₃NH₃PbCl₃ single crystals with dimension of about 4 mm×3 mm×3 mm were grown by evaporation and inversion crystallization method. Powder X-ray diffraction (PXRD) of the obtained crystals powder showed that the crystals were of cubic structure, and their lattice constants were 0.56833 nm and 0.56891 nm, respectively. Fourier transform-infrared (FT-IR) and Raman spectra of the crystals were measured and the peaks were assigned. The optical properties were characterized by UV-VIS-NIR and photoluminescence spectroscopy. The results showed that the absorption edge of CH₃NH₃PbCl₃ crystal was about 423 nm, with the photoluminescence peak at 433 nm, the band gap at 2.97 eV. As compared with the optical properties of CH₃NH₃PbCl₃ thin films, CH₃NH₃PbCl₃ single crystal has application advantages in solar cell. Finally, the band structure of CH₃NH₃PbCl₃ crystal was studied by the first principle, and the band gap value was calculated to be 2.428 eV, which was in good agreement with the present experimental result.

Dy³⁺ doped Bi₄Si₃O₁₂ (BSO) crystals were grown by the vertical Bridgman method with doping contents of 0.1mol%, 0.2mol%, 0.3mol%, 2mol%, 3mol% and 4 mol%. It was found that the crystallization behavior was modified by heavy doping and the surface precipitated phase disappeared gradually with the dopant content increase. The maximum light yield of the BSO crystals doped with 0.1mol% Dy³⁺ was up to 145% of that of pure BSO. The thermo-luminescence (TL) spectra showed that the intensity of TL peaks increased slightly and Dy³⁺ doping is helpful to light yield when doping content is less than 0.3mol%. However, it induced more defects when the dopant content was larger than 2mol%. High doping may lead to competitive luminescence between Dy³⁺ ions and Bi³⁺ ions, resulting in decrease of light yield.

Pure YVO₄ crystal and YVO₄ crystal doped with different Ce concentrations were grown by Czochralski method. XRD pattern shows Ce³⁺ ion enters the YVO₄ lattice by occupying the Y³⁺ site and the crystal structure was not significantly changed. The detection of UV excitation spectrum and emission spectrum of YVO₄: Ce³⁺ at room temperature showed that excited at 325 nm the YVO₄: Ce³⁺ emits two spectra. The main emission spectrum at 445 nm is a broadband peak, caused by transition of ²D_3/2→²F_5/2 of Ce³⁺. The other one is a weak peak emission centered around 620 nm, which presents the emission of V⁴⁺. With increase of Ce mole fraction from 1at% to 8at%, the blue emission intensity gradually increases to a maximum value. As Ce fraction increases to 10.0at%, the emission intensity decreases gradually, indicating an obvious concentration quenching. The red emission intensity gradually increases to a maximum value when Ce fraction increases to 10.0at%. Detection by X-ray photoelectron spectroscopy (XPS) shows that Ce⁴⁺ and V⁴⁺ ions coexist in YVO₄:Ce³⁺, which may result from some of the Ce³⁺ losing electrons to be oxidized into Ce⁴⁺, and most of them being captured by the V⁵⁺ ions and, therefore, resulting in V⁵⁺→V⁴⁺ transformation. Based on V⁴⁺ d orbital splitting into ²A₁, ²B₁, ²B₂, and ²E, the 620 nm red emission under 325 nm and 450 nm excitation probably originated from electronic transitions between the V⁴⁺splitted d orbits. In conclusion, present analytical data of the luminescence spectra of YVO₄: Ce³⁺ provide a theoretical support for YVO₄:Ce³⁺ emitting red light and blue light simultaneously under UV excitation.

Tb³⁺ and Yb³⁺ co-doped Sr₂B₂O₅ phosphors were synthesized by conventional solid-state reactions. The obtained Sr₂B₂O₅: Tb³⁺, Yb³⁺ phosphors were characterized by X-ray diffraction (XRD) and photoluminescence (PL) spectra. XRD results show that all prepared phosphors can be readily indexed to pure monoclinic phase of Sr₂B₂O₅. The dominant excitation at 374 nm was observed among three strong excitation peaks located at 354, 374 and 487 nm monitored at 543 nm and 980 nm, by which Sr₂B₂O₅ phosphors could be considered as having a strong absorption in the near ultraviolet region of sunlight. Under the ultraviolet light excitation at 374 nm, the strong intensity of visible emission from Tb³⁺: ⁵D₄→⁷F_J ( J = 6, 5, 4, 3), and near-infrared (NIR) emission from Yb³⁺ (²F_5/2→²F_7/2) were detected. The relationship between the luminescence spectra and Yb³⁺ doping content demonstrated the monoclinic Sr₂B₂O₅ exhibited the excellent quenching concentration.

Monodispersed (Y, Eu)₂O₃ spheres (110-550 nm in diameter) were calcined from precursors synthesized via homogeneous precipitation. Systematic characterizations of the products were carried out by XRD, FE-SEM, TEM, and PLE/PL analyses. Large spherical particles were resulted via seeded growth and NH₄NO₃ addition. Calcining the basic carbonate precursor at 600℃ yielded cubic (Y, Eu)₂O₃. The spherical shape and excellent dispersion of the precursor particles were largely retained to the oxides after annealing up to 1000℃. The polycrystalline (Y, Eu)₂O₃ spheres exhibited typical red emission at 615 nm (the ⁵D₀→⁷F₂ transition of Eu³⁺) under UV excitation at 242 nm. The phosphors showed a substantially size-dependent luminescent behavior. Shorter fluorescence lifetime (1.15-1.57 ms), decreased asymmetry factor (I(⁵D₀→⁷F₂)/I(⁵D₀→⁷F₁)) of luminescence, and enhanced luminescent intensity were observed along with increasing particle size.

(Ca, Cr) co-doped YAG ceramics were synthesized by high temperature solid state reaction. The effects of Ca²⁺ and Cr³⁺ ions doping on the infrared emission properties of YAG ceramics were investigated. X-ray diffraction results showed that the phase composition of the prepared samples were yttrium aluminum garnet, which indicated that the Ca²⁺ and Cr³⁺ irons were incorporated into the crystal lattice of yttrium-aluminate garnet structure. Infrared absorption results showed that the infrared absorptivity of the (Ca, Cr) co-doped samples was 0.90, which was 29 times higher than that of the pure YAG sample (0.03). The band gap of YAG ceramics were decreased 1.77 eV by Ca²⁺ and Cr³⁺ co-doping based on calculation of the absorbance test results. Therefore, the absorption of the free carrier was improved, which is the main reason why the (Ca, Cr) co-doping YAG ceramics have a high emissivity in near infrared wavelength.

Cerium and Praseodymium co-doped Lu₃Al₅O₁₂ nanocrystalline powders were synthesized by reverse titration, using ammonium hydroxide (NH₄OH) and ammonium hydrogen carbonate (NH₄HCO₃) mixed precipitator. The optical properties of 0.25at%Pr: LuAG ceramics doped with 0, 0.1at%, 0.2at% and 0.3at% Ce³⁺ ions were measured. The Ce, Pr: LuAG powders showed a weak agglomeration with a primary particle size of about 60 nm after calcining at 1200℃ for 2 h. Ce, Pr co-doped LuAG transparent ceramics were obtained after green compacts were cold isostatic pressed and sintered in flowing H₂ atmosphere at 1800℃ for 6 h. The in-line transmittance of the double face polished Ce, Pr co-doped LuAG ceramic at 800 nm wavelength was 82%. The X-ray excited emission spectrum showed that the emission intensity at 550 nm wavelength was enhanced in Ce, Pr co-doped LuAG transparent ceramics by energy transfer from 5d-4f of Pr³⁺ ions to Ce³⁺ ions, and the emission intensity reached maximum value when the dopant contents were 0.2at%Ce and 0.25at%Pr.

A series of Europium (Eu) and Strontium (Sr) codoped hydroxyapatite samples (Ca_10-x-Sr_x-HAp: Eu) were designed and prepared using the chemical co-precipitation method. The crystalline structure, chemical composition and luminescent property of samples were characterized by X-ray diffraction (XRD) and photoluminescent spectrum (PL). XRD patterns showed that Eu doping had little effect on the structure of the samples, while with the increase of Sr content, crystallinity and interplanar crystal spacing were increased. PL spectra indicate that the fluorescence intensity at 596 nm and 618 nm of Ca-Sr-HAp: Eu samples increased firstly and then decreased with increase of Sr content at 394 nm excitation, and the strongest peak appeared in the Ca₃-Sr₇-HAp: Eu samples. At the same time, the fluorescence lifetime of the samples showed the same tendency with the increase of Sr content. In addition, the ratio of magnitude between electric dipole and magnetic dipole transition (I_R/I_O) also increased firstly and decreased subsequently along with the increase of Sr content in the matrix. Furthermore, the energy transfer parameters (f) calculated from luminescent dynamic of Eu³⁺ correlating to different sites and transitions present the reverse change. It is concluded that the doped sites of Eu³⁺ ions in the host lattice are affected by the content and location of Sr²⁺ ions in the matrix. Thereby a tunable luminescent property of Ca_10-x-Sr_x-HAp: Eu samples can be obtained by changing the site of Eu ions in the matrix through adjusting the value of Sr/Ca.

Europium ions doped yttrium vanadate (YVO₄: Eu³⁺) has excellent emission properties for down-conversion applications. However, the serious surface defects of YVO₄: Eu³⁺ hinder the improvement of luminescent efficiency. In order to improve the particle size distribution and morphology of YVO₄: Eu³⁺ nano-powders, mono-dispersed spherical YVO₄: Eu³⁺@SiO₂ core-shell structure materials were prepared by coating a layer of YVO₄: Eu³⁺ onto the surface of SiO₂ microspheres. With the shell-core ratio setting as 0.6, the luminescence intensity of YVO₄: Eu³⁺@SiO₂ core-shell structure composite could reach up to more than 90% of pure YVO₄: Eu³⁺ nano-powder. Furthermore, the prepared YVO₄: Eu³⁺@SiO₂ core-shell structure films were used as down-conversion materials for amorphous silicon thin film solar cells. The cell parameters such as short current density and photoelectric conversion efficiency increased from original 6.694 mA/cm² and 9.40% to 8.417 mA/cm² and 10.15%, respectively. Thus YVO₄: Eu³⁺@SiO₂ core-shell configuration can be fabricated from YVO₄: Eu³⁺ and SiO₂ microsphere to avoid agglomeration. The prepared YVO₄: Eu³⁺@SiO₂ core-shell structures have regular morphology and uniform particle sizes, which are suitable to be used as down-conversion light emitting layer in amorphous silicon solar cells.

The natural dye was extracted from Lycium ruthenicum Murray which was cultivated in Tibetan Plateau. The UV-Vis absorption spectra and cyclic voltammetry were used to characterize the dyes and confirm the optimal pH of the dye solutions. The influence of different contents of ethyl cellulose(EC) on the performance of electric catalytic of graphene nanoplates(GNs) counter electrode were investigated through electrochemical impedance spectra, cyclic voltammetry and Tafel polarization curve. DSCs were assembled by using the natural pigments with optimal pH as sensitizers and the GNs counter electrode with different contents of EC as counter electrode. It was found that the GNs counter electrode with 10wt% EC achieved the best performance of electric catalytic. The highest power conversion efficiency of the GNs counter electrode with 10wt% EC was 0.92%, close to that of Pt counter electrode (0.99%).

Graphene quantum dots containing nitrogen (NGQDs) were synthesized by the hydrothermal method. AFM, TEM and XPS were employed to investigate the morphology and composition of NGQDs, and their optical properties were studied by UV-Vis and photoluminescent (PL) spectroscopy. AFM and TEM images showed that NGQDs were about 8.9 nm in size and 0.6-2.0 nm in thickness (1-3 layers graphene). The result of XPS showed that nitrogen content in NGQDs was ~17% and nitrogen existed mainly in the form of "pyrrolic N". Spectroscopy experiments indicated that excitation spectra of NGQDs were similar to their absorption spectra, and their emission spectra were excitation-independent. In addition, quantum yield of NGQDs was calculated to be ~18%, increasing with the content of nitrogen in NGQDs increase. Furthermore, the lifetime decay curve was well fitted to a double exponential decay curve (τ₁=2.93 ns, τ₂=9.00 ns), which indicates that there are two feature chromophores in NGQDs. The chromophores are sp² clusters with oxygen groups and pyrrolic ring.

A new two-dimensional layered hybrid perovskite solar-cell absorber was synthesized by one-step method, using (EDA)I₂, (FA)I, and PbI₂ with a 1:2:3 stoichiometric ratio in a solvent mixture of N, N-dimethylformamide(DMF). Ethylenediamine(EDA) cation was introduced into the perovskite lattice to synthesize a layered structure with improved resistance to the degradation by humidity in air. The effects of humidity and time on crystal structure, composition, morphology, and absorption spectra of (EDA)(FA)₂[Pb₃I₁₀] and CH₃NH₃PbI₃ were analyzed by in situ grazing incidence X-ray diffraction(GIXRD), X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope(AFM), and UV-Vis spectroscope. The results reveal that the prepared (EDA)(FA)₂[Pb₃I₁₀] film is more moisture resistant than the CH₃NH₃PbI₃ film which is widely used in the perovskite solar cell. SEM analysis reveals that the (EDA)(FA)₂[Pb₃I₁₀] film has a layered structure, which can reduce the degradation caused by moisture. What’s more, UV-Vis light absorption spectroscopy and atomic force microscopy(AFM) results show that the layered structure film is also a suitable absorber for perovskite solar cells. Photoluminescence spectrum(PL) reveals that bandgap of the (EDA)(FA)₂[Pb₃I₁₀] film is 1.67 eV, which is close to the optimum value for solar photoelectric conversion. As compared to CH₃NH₃PbI₃ film, the low-cost perovskite structure offers greater tunability on a molecular level for further material optimization and possibility for widely used in the future.

Different In₂Se₃/CuSe nano-powders were successfully fabricated by ultrasound and microwave solvothermal, atmospheric pressure, or high pressure solvothermal methods. Then the thin film solar cell absorbent layer was prepared through coated-rapid heating treatment system using above nano-powders. The phase, morphology and composition of the powders and CIS film were characterized by XRD, Raman, FESEM, and TEM. The results showed that the ultrasonic microwave solvothermal and atmospheric pressure solvothermal methods produced a mixture of In₂Se₃/CuSe. However, high pressure solvothermal method obtained core-shell structure In₂Se₃/CuSe powders (In₂Se₃-core, CuSe-shell). In addition, FESEM analysis revealed that the In₂Se₃/CuSe powders prepared by high pressure solvothermal method were easier to produce smooth and dense CIS film. The fabricated CIS thin-film solar cell was demonstrated its photoelectric conversion property with open-circuit voltage of 50 mV and short-circuit current density of 8 mA/cm².

CIGS target was prepared by one step hot-pressing sintering using CuIn_0.7Ga_0.3Se₂, In_0.7Ga_0.3Se and CuSe as precursor powder. Archimedes method, XRD, Raman, SEM, and EDS were carried out to investigate the effects of liquid-assisted sintering on the relative density, phase, structure, morphology, and composition of CIGS target. The results showed that CuSe would turn into liquid phase when temperature was increased to the liquid phase points. The liquid phase can significantly reduce sintering temperature (about 50℃ dropping) and accelerate the sintering process. When sintered at 575℃, the target can obtain the relative density of 96.18%, single phase, dense microstructure with good grain growth. In addition, using the target with molar ratio of Cu : In : Ga : Se =23.0 : 18.2 : 6.5 : 52.3, CIGS thin films were also prepared by sputtering-heat treatment, followed assembled into AZO/ZnO/CdS/CIGS/Mo solar cell. The fabricated CIGS solar cells presented a photoelectric conversion efficiency of 9.6%.

Using stoichiometric Si(OC₂H₅)₄ and Bi(NO₃)₃·5H₂O as precursors and citric acid as solvent, polycrystalline Bi₄Si₃O₁₂ (BSO) powders were synthesized by Sol-Gel method and sintered at high temperature. Batch production of 250 g powders was realized. Using as-synthesized BSO powders and <001>-oriented BSO seeds, BSO crystals were grown in the vertical Bridgman furnace. The crystallization behavior was discussed and high quality BSO crystal up to 30 mm × 30 mm × 210 mm was obtained. The scintillation characteristics of BSO single crystals were investigated. The energy resolution of the BSO crystal was 18.9% and the relative light yield of the crystal was 7.2% compared with CsI(Tl) at the same conditions.

Ce-doped Gd₃(Al,Ga)₅O₁₂ (GAGG) precursors were co-precipitated from a mixed solution of gadolinium, aluminum and gallium nitrates using ammonium hydroxide as precipitant. and then characterized by TG/DTA analysis. GAGG powders were obtained by calcining the precursors at 800℃, 850℃, 900℃, 1000℃, 1100℃ and 1200℃. Phase evolution of GAGG powders were investigated by XRD analysis which showed that a pure GAGG phase was obtained. SEM observation demonstrated that the obtaimed poovders were mainly amorphous with size mainly about 100-150 nm in diameter. PL spectra of GAGG powders showed strong emission around 560 nm. The highest transparency of as prepared ceramic was obtained when GAGG powders were calcined at 900℃.