Co-doped Borosilicate Glasses Research Articles

Adjusting photoluminescence of high thermostability Dy3+/Eu3+ co-doped borosilicate glass for white LED device

Due to the adoption of fluorescent powder encapsulated by organic resin, commercial light emitting diodes (LEDs) suffer from low thermal stability and poor light quality under high temperature, and luminescent glass is one of the effective ways to solve this problem. A series of borosilicate (B2O3–SiO2–Al2O3–PbO-Dy2O3–Eu2O3, marked as BSAP: DyEu) was prepared by the gas suspension technique. The basic characterization test indicate that the prepared glass has excellent thermal stability and stable structure. The optical properties of the luminescent glass were investigated in detail. By changing the Eu3+ doping amount, the Dy3+/Eu3+ co-doped glass can realize warm white light emission. The temperature-variable fluorescence spectra of BASP: Dy1.25Eu1.0 were analyzed, and the glass can produce strong warm white light emission in a wide temperature range. At 700 K, the luminous intensity of the glass remains above 38.49 % of the room temperature, and the chroma shift ΔC = 8.57 × 10−3. In addition, the w-LED device based on commercial GaN chip and BSAP: DyEu glass realizes warm white light output with excellent correlated color temperature (3063 K) and high color rendering index (90.3). The analysis shows that Dy3+/Eu3+ co-doped borosilicate glass can be used as a candidate material for w-LED applications.

Spectral Characterization of Nd3+/Yb3+Co-Doped Borosilicate Glasses for Photonic and Laser Systems Applications

Spectral Characterization of Nd3+/Yb3+Co-Doped Borosilicate Glasses for Photonic and Laser Systems Applications

Enhancement 2.0 μm fluorescence properties of Er3+/Ho3+ co-doped borosilicate glasses in the presence of Li+ ions for mid-infrared lasers

Abstract The effect of Li+ ion concentration on mid-infrared (MIR) emission of Ho3+/Er3+ co-doped borosilicate glasses was reported. X-ray diffractometer (XRD) curves confirmed the amorphous structure of the glass. With the introduction of Li+ ions, the [BO3] in the glass network structure was observed to increase while the destruction of [BO4]. The introduction of Li+ ions will make the distance between Er3+ ions and Ho3+ ions in the glass structure closer. The increase of Li+ ions will lead to the polarization of Er3+ ion electron cloud, which is conducive to the energy transfer between Ho3+ and Er3+ as well as the enhanced the emission of 2.0 μm with a full-width at half-maximum (FWHM) of 192 nm. According to the fluorescence decay curve, the energy transfer efficiency of Li+ ion doped sample is up to 80.1%. These above results indicate that the prepared sample is a potential substrate for 2.0 μm MIR lasers.

Enhanced, shortened and tunable emission in Eu3+ doped borosilicate glasses by Cu+ co-doping

A series of Cu+/Eu3+ co-doped borosilicate glasses have been successfully prepared by melt-quenching method. As proved by transmission spectra, the copper ions are univalent in the investigated borosilicate glasses. Under ultraviolet (UV) excitation at 325 nm, the emission intensity of Eu3+ increased by nearly double due to a large overlapping between the Cu+ and Eu3+ emission peaks. The decreased excitation intensity in UV region and shortened emission lifetime of Cu+ in association with presence of Eu3+ ions consistently suggest an energy transfer process from Cu+ to Eu3+ ions. On the other hand, the partially allowed transition of Cu+ makes contribution to the red emission of Eu3+ at 611 nm in Cu+/Eu3+ co-doped samples, thus shortening the lifetime from the conventional millisecond (∼1.86 ms) to the microsecond (up to around 37 μs) regime. Besides, tunable light is realized by combining the blue-green emission from Cu+ ions with the orange-red one from Eu3+ ions. The light can be continuously tuned by changing the Cu+/Eu3+ concentration ratio, indicating that the present novel Cu+/Eu3+ co-doped borosilicate glasses are potential as fast response and tunable photoluminescence materials.

Blue upconversion luminescence for Yb3+/Tm3+ co-doped borosilicate glasses

A new kind of Yb3+/Tm3+ co-doped blue-emitting borosilicate glass was prepared by melting and quenching process. The Judd–Ofelt intensity parameters were calculated and discussed according to the recorded absorption spectrum. Strong blue upconversion emissions originated from the 1G4→3H6 transition of Tm3+ were observed under 980nm excitation. It is suggested that the conversion of blue radiation is dominated by a three-photon absorption process. The optimized concentration of Yb3+ and Tm3+ was determined to be 0.6mol% and 0.075mol% based on the emission performance. The energy transfer process from Yb3+ to Tm3+ was analyzed and the energy transfer efficiency can reach up to 68%. The enhanced blue upconversion emission indicates that the Yb3+/Tm3+ co-doped borosilicate glass can be potential for applications of displays and blue lasers.

Spectroscopic properties and energy transfer study of Nd3+/Yb3+ co-doped in borosilicate glass for 1.0 μm emission

The Nd3+/Yb3+ co-doped borosilicate glasses are fabricated by using a conventional melt quenching technique in air atmosphere. The Spectroscopic properties of 1.0μm emission in Nd3+/Yb3+ co-doped borosilicate glasses are investigated under 808nm excitation. The luminescence decay curves show a nonexponential character, the energy transfer microscopic parameters and transfer efficiencies are calculated. Results indicate that the energy transfer takes place via nonradiative electric dipole–dipole processes and is enhanced with the concentration of Nd3+ donor ions. The glass co-doped with 0.5mol% Nd2O3 and 2mol% Yb2O3 has a large microscopic parameters 100×10−40cm6s−1, high transfer efficiencies 73.58% and long fluorescence lifetime 0.3ms at 1020nm, which is of great potential as a candidate material in the development of multiple-pump-channel Yb3+ fiber lasers.

Thermal quenching and energy transfer in novel Bi3+/Mn2+co-doped white-emitting borosilicate glasses for UV LEDs

Tunable white-emission due to efficient energy transfer has been demonstrated in Bi3+/Mn2+co-doped borosilicate glasses.

Luminescence property of Ce3+-Tb3+-Sm3+ co-doped borosilicate glass under various ultraviolet excitations

Ce3+-Tb3+-Sm3+ co-doped white light emitting borosilicate glasses were fabricated by high-temperature melting technique. In this paper, the excitation spectra and the emission spectra of Ce3+, Tb3+ and Sm3+ ions-doped and co-doped samples were measured and the energy transfer mechanism of Ce3+, Tb3+, and Sm3+ were studied by analyzing the fluorescence lifetime of single-doped and co-doped samples. The color coordinate, rendering index, and color temperature of the emission spectra can be adjusted by changing the excitation wavelength of ultraviolet LED. Finally, we have obtained the white light which fits for life, study, and work.

White light luminous properties and energy transfer mechanism of rare earth ions in Ce3+/Tb3+/Sm3+ co-doped glasses

We report on a kind of Ce3+/Tb3+/Sm3+ co-doped borosilicate glasses which can emit white light luminescence combined with red, green and blue fluorescence. In this manuscript, the energy transfer mechanism between Ce3+ and Tb3+ ions, Ce3+ and Sm3+ ions, and Tb3+ and Sm3+ ions is discussed by analysis of the steady and transient luminescence spectra of the doped ions. Based on the energy transfer mechanism, the near-ideal white light emission from the Ce3+/Tb3+/Sm3+ co-doped glasses with the color coordinate (x=0.335, y=0.337) has been observed under 350-nm excitation. Meanwhile, the calculated parameters such as color rendering index (78–81) and color temperature (4717–5372 K), characterizing luminous properties, show that the glasses can be potential candidates for displays and lighting.

Tunable white luminescence and energy transfer in novel Cu^+, Sm^3+ co-doped borosilicate glasses for W-LEDs

The luminescent properties of novel Cu⁺, Sm³⁺ single- and co-doped borosilicate glasses were systematically investigated by absorption, excitation, emission spectra and decay curves. Cu⁺ single-doped glasses emit broad luminescence band covering all the visible range. And their peaks shift to blue with decreasing excitation wavelength from 330 to 280 nm. Cu⁺, Sm³⁺ co-doped samples generate the varied hues from blue white to pure white and eventually to yellow white due to an efficient energy transfer from Cu⁺ to Sm³⁺. Our research indicates the potential application of Cu⁺, Sm³⁺ co-doped borosilicate glasses as converting phosphors for white LEDs pumped by UV LED chips.

Optical parameters of Nd3+:Er3+:Yb3+ co-doped borosilicate glasses and their energy transfers at high temperature

This paper reports that a series of Nd3+:Er3+:Yb3+ co-doped borosilicate glasses have been prepared and their absorption spectra measured. The J—O intensity parameters Ωk (k = 2, 4, 6), spontaneous radiative lifetime τrad, spontaneous transition probability A, fluorescence branching ratio β and oscillator strength fed of the Nd3+ ions at room temperature are calculated based on Judd—Ofelt (J—O) theory. The temperature dependence of the up-conversion photoluminescence characteristics in a Nd3+:Er3+:Yb3+ co-doped sample is studied under a 978 nm semiconductor laser excitation, and the energy transfer mechanisms among Yb3+, Er3+ and Nd3+ ions are analysed. The results show that the J—O intensity parameters Ω2 increase when the Nd3+ concentration of the Nd3+:Er3+:Yb3+ co-doped borosilicate glasses increases. The possibility of spontaneous transition is small and lifetimes are long at levels of 4F5/2 and 4F3/2. The intensity of Nd3+ emissions at 595, 691, 753, 813 and 887 nm are markedly enhanced when the sample temperature exceeds 400 K. The reasons being the cooperation of the secondary sensitization from Er3+ to Nd3+ and the contribution of a multi-phonon.

Er3+-Yb3+ codoped borosilicate glass for optical thermometry

Infrared to green up-conversion emissions centered at the wavelengths of about 524 and 550 nm of the Er3+-Yb3+ codoped borosilicate glass are recorded, using a 978 nm semiconductor laser diode (LD) as an excitation source. The fluorescence intensity ratio (FIR) of the green up-conversion emissions at about 524 and 550 nm in the Er3+-Yb3+ codoped borosilicate glass has been studied as a function of temperature over the temperature range of 295–873 K. The maximum sensitivity and the temperature resolution derived from the FIR of the green up-conversion emissions are approximately 0.0038 K−1 and 0.2 K, respectively. It is demonstrated that the prototype optical temperature sensor based on the FIR technique from the green up-conversion emissions in the Er3+-Yb3+ codoped borosilicate glass plays a major role in temperature measurement.

Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses

Yb3+:Er3+:Tm3+co-doped borosilicate glasses are prepared. Their strong up-conversion photoluminescence spectra in a range from ultra-violet to near-infrared, which are excited by a 978-nm laser diode, are measured, and the mechanisms of energy transfer among Yb3+, Er3+ and Tm3+ ions are discussed. The results show that there is an unexpected wavelength at 900-nm emission from Yb3+ Stark splitting levels to pump Tm3+ ions and there exists an optimum pump power. The concentration of the Tm3+ dopant gives rise to a prominent effect on the intensity of visible and near-infrared emissions for the Yb3+:Er3+:Tm3+ co-doped borosilicate glasses.

Cooperative Quantum Cutting in Yb$^{3+}$–Tb$^{3+}$ Codoped Borosilicate Glasses

Quantum cutting down-conversion (DC) with the emission of two near-infrared photons for each blue photon absorbed is realized in Yb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -Tb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> codoped borosilicate glasses. With the excitation of Tb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ion by a 484-nm monochromatic light, emission from the <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5/2</sub> rarr <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> F <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7/2</sub> transition of Yb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ions is observed and this emission is proved to originate from the DC between Tb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ions and Yb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ions. Results shows that maximum quantum efficiency reach as high as 153%, which is comparable with that in oxyfluoride glass ceramics in this system. With the advantages of excellent transparence, easy shaping, good stability, and low cost, Yb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -Tb <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> codoped borosilicate glasses are potentially used as down-converter layer in silicon-based solar cells.

Significant temperature effects on up-conversion emissions of Nd3+:Er3+:Yb3+ co-doped borosilicate glass and its thermometric application

Abstract The significant temperature effects on up-conversion emissions of Nd 3+ :Er 3+ :Yb 3+ co-doped borosilicate glass excited by a 978-nm semiconductor laser have been investigated and two-stage sensitization of Yb 3+ → Er 3+ → Nd 3+ is discussed. The fluorescence intensity ratio of the near-infrared emission at 813 and 887 nm of Nd 3+ ions takes on trustworthy repeatability in the temperature range of 296–670 K because of their strong photoluminescence intensities and the sample is more suitable for sensitive high-temperature sensor.

镱铒共掺硼硅酸盐玻璃可见光波段扎得-奥菲而特理论分析

镱铒共掺硼硅酸盐玻璃可见光波段扎得-奥菲而特理论分析