Near Infrared Quantum Cutting for Solar Cells in CeF3:Yb3+ Nanophosphors

2011 ◽  
Vol 366 ◽  
pp. 215-218 ◽  
Author(s):  
Su Wen Li

The CeF3 nanophosphors with Yb3+ concentrations from 0 to 8% had been prepared by hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). Their photoluminescence properties including excitation spectra, Uv-visibe and near infrared (NIR) emission spectra and fluorescence dynamics were studied. In the CeF3: Yb3+ nanophosphors an intensity infrared emission originated from Yb3+2F5/2 - 2F7/2 transition at 900-1050 nm matching to the energy of Si band gap of Si-based solar cells was observed under the excitation of 5d level of Ce3+. The lifetime of Ce3+ decreases and the quantum efficiency (QE) increases with increasing Yb3+ concentration.

2011 ◽  
Vol 366 ◽  
pp. 173-176 ◽  
Author(s):  
Su Wen Li

An efficient near-infrared (NIR) quantum cutting (QC) nanophospors with Ce3+, Yb3+ codoped in CaF2 had been synthesized by hydrothermal method and characterized by X-ray powder diffraction, scanning electron microscope, transmission electron microscopy, photoluminescence spectra and decay dynamics. The nanoparticles were uniform and monodisperse. Under the excitation of 5d level of Ce3+, an intense NIR emission at 900-1050nm was observed which match to the energy of Si band gap of Si - based solar cells. In the Ce3+, Yb3+ codoped CaF2, the lifetime of Ce3+ decreases Superscript textand the quantum efficiency (QE) increases with increasing Yb3+ concentration.


2016 ◽  
Vol 16 (4) ◽  
pp. 3577-3582
Author(s):  
Sun Xiao ◽  
Hu Xiao-Yun ◽  
Hou Wen-Qian ◽  
Fan Jun ◽  
Miao Hui ◽  
...  

In this paper, Tb3+–Yb3+ Co-doped CeF3 nanophosphors were synthesized using the microwave-assisted heating hydrothermal method (M–H). The excitation and emission spectra of the samples at room temperature show that the samples absorb ultraviolet light from 250 nm to 280 nm, and emit light at 300 nm. This corresponds to the transitions from 5D to 4F of Ce3+, 480 nm, 540 nm, 583 nm, 620 nm which correspond to the transitions from 5D4 to 7F6,5,4,3 of Tb3+, 973 nm which corresponds to the transitions from 2F5/2–2F7/2 of Yb3+. In the emission spectra, it is clear that the emission intensity of Ce3+ and Tb3+ decreases, and Yb3+ increases with increasing Yb3+. This suggests that energy transfer from Ce3+ to Yb3+, and Ce3+ to Tb3+ to Yb3+ may occur. In the near infrared emission area, it is noted that a distinct emission centered at 973 nm was observed under 260 nm excitation. This is due to transitions among the different Stark levels of 2FJ(J=5/2, 7/2) Yb3+ ions. This also suggests an energy transfer from Ce3+ ions to Tb3+ and then to Yb3+. The energy transfers from Tb3+–Yb3+ Co-doped CeF3 nanophosphors, which lead to intense NIR emissions at 900–1050 nm, match the energy of Si band gaps of Si-based solar cells. Therefore, these kinds of materials are promising candidates for applications that require modifying if solar spectrums and enhancement of conversion efficiency of Si-based solar cells.


2021 ◽  
Vol 9 ◽  
Author(s):  
Karmel de Oliveira Lima ◽  
Luiz Fernando dos Santos ◽  
Rodrigo Galvão ◽  
Antonio Claudio Tedesco ◽  
Leonardo de Souza Menezes ◽  
...  

Among several optical non-contact thermometry methods, luminescence thermometry is the most versatile approach. Lanthanide-based luminescence nanothermometers may exploit not only downshifting, but also upconversion (UC) mechanisms. UC-based nanothermometers are interesting for biological applications: they efficiently convert near-infrared radiation to visible light, allowing local temperatures to be determined through spectroscopic investigation. Here, we have synthesized highly crystalline Er3+, Yb3+ co-doped upconverting KGd3F10 nanoparticles (NPs) by the EDTA-assisted hydrothermal method. We characterized the structure and morphology of the obtained NPs by transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and dynamic light scattering. Nonlinear spectroscopic studies with the Er3+, Yb3+: KGd3F10 powder showed intense green and red emissions under excitation at 980 and 1,550 nm. Two- and three-photon processes were attributed to the UC mechanisms under excitation at 980 and 1,550 nm. Strong NIR emission centered at 1,530 nm occurred under low 980-nm power densities. Single NPs presented strong green and red emissions under continuous wave excitation at 975.5 nm, so we evaluated their use as primary nanothermometers by employing the Luminescence Intensity Ratio technique. We determined the temperature felt by the dried NPs by integrating the intensity ratio between the thermally coupled 2H11/2→4I15/2 and 4S3/2→4I15/2 levels of Er3+ ions in the colloidal phase and at the single NP level. The best thermal sensitivity of a single Er3+, Yb3+: KGd3F10 NP was 1.17% at the single NP level for the dry state at 300 K, indicating potential application of this material as accurate nanothermometer in the thermal range of biological interest. To the best of our knowledge, this is the first promising thermometry based on single KGd3F10 particles, with potential use as biomarkers in the NIR-II region.


2008 ◽  
Vol 8 (3) ◽  
pp. 1410-1413 ◽  
Author(s):  
Shaozhe Lü ◽  
Jishen Zhang

La3PO7:Eu3+ samples were prepared by combustion and annealing and characterized by X-ray diffraction and transmission electron microscopy. It was found that the average size of the particles is about 80 nm. The red emission from the 5D0 → 7F2 transition of the Eu3+ ions under ultraviolet light excitation is much stronger than the orange emission from the 5D0 → 7F1 transition. The emission spectra, charge transfer band, laser selective excitation spectra, and time-resolved spectra indicate that symmetry of the local environment of Eu3+ lacks an inversion center and Eu3+ ions occupy at least two types of sites in the La3PO7 crystal. The superior color chromaticity compared to other phosphates and borates doped with Eu3+ means La3PO7:Eu3+ may have potential as a luminescent material.


Author(s):  
T. Zhezhera ◽  
P. Gluchowski ◽  
M. Nowicki ◽  
M. Chrunik ◽  
A. Majchrowski ◽  
...  

Abstract An efficient near-infrared quantum cutting process by cooperative down-conversion of active Bi3+ and Nd3+ ions was demonstrated in Bi3TeBO9:Nd3+ phosphors. In particular, the near-infrared emission of Nd3+ ions enhanced by Bi3+ ions of a series of novel Bi3TeBO9:Nd3+ microcrystalline powders doped with Nd3+ ions in various concentrations was investigated. In order to investigate the luminescent properties of BTBO:Nd3+ powders, the excitation and emission spectra and the fluorescence decay time were measured and analyzed. In particular, the emission of Bi3TeBO9:Nd3+ at 890 and 1064 nm was excited at 327 nm (via energy transfer from Bi3+ ions) and at 586.4 nm (directly by Nd3+ ions). The highest intensity emission bands in near-infrared were detected in the spectra of Bi3TeBO9:Nd3+ doped with 5.0 and 0.5 at.% of Nd3+ ions upon excitation in ultraviolet and visible spectral range, respectively. The fluorescence decay lifetime monitored at 1064 nm for Bi3TeBO9:Nd3+ powders shows the single- or double-exponential character depending on the concentrations of Nd3+ ions. The possible mechanisms of energy relaxation after excitation Bi3TeBO9:Nd3+ powders in ultraviolet or visible spectral range were discussed. The investigated Bi3TeBO9:Nd3+ phosphors efficiently concentrate the ultraviolet/visible radiation in the near-infrared spectral range and can be potentially used as effective spectral converters. Graphical abstract


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1425
Author(s):  
José J. Velázquez ◽  
Giulio Gorni ◽  
Rolindes Balda ◽  
Joaquin Fernández ◽  
Laura Pascual ◽  
...  

Transparent oxyfluoride glass–ceramics containing NaGdF4 nanocrystals were prepared by melt-quenching and doped with Er3+ (0.5 mol%) and different amounts of Yb3+ (0–2 mol%). The selected dopant concentration the crystallization thermal treatments were chosen to obtain the most efficient visible up-conversion emissions, together with near infrared emissions. The crystal size increased with dopant content and treatment time. NaGdF4 NCs with a size ranging 9–30 nm were obtained after heat treatments at Tg + 20–80 °C as confirmed by X-ray diffraction and high-resolution transmission electron microscopy. Energy dispersive X-ray analysis shows the incorporation of rare earth ions into the NaGdF4 nanocrystals. Near-infrared emission spectra, together with the up-conversion emissions were measured. The optical characterization of the glass–ceramics clearly shows that Er3+ and Yb3+ ions are incorporated in the crystalline phase. Moreover, visible up-conversion emissions could be tuned by controlling the nanocrystals size through appropriated heat treatment, making possible a correlation between structural and optical properties.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 121
Author(s):  
Joanna Pisarska ◽  
Wojciech A. Pisarski ◽  
Radosław Lisiecki ◽  
Witold Ryba-Romanowski

In this work, spectroscopic properties of europium and erbium ions in heavy metal oxide glasses have been studied. The phonon energy of the glass host was determined based on Eu3+ excitation spectra measurements. Near-IR emission spectra at 1550 nm related to 4I13/2 → 4I15/2 transition of erbium in heavy metal glasses were examined with special regards to luminescence bandwidth and measured lifetime. In particular, correlation between phonon energy and the measured lifetime 4I13/2 (Er3+) was proposed. The luminescence lifetime for the 4I13/2 upper laser state of erbium decreases with increasing phonon energy in glass matrices. Completely different results were obtained glass samples with europium ions, where the 5D0 lifetime increases with increasing phonon energy. Our investigations suggest that the values of measured 5D0 lifetime equal to radiative lifetimes for all heavy metal oxide glasses.


2016 ◽  
Vol 16 (4) ◽  
pp. 3522-3526 ◽  
Author(s):  
Bingyu Xu ◽  
Mingxia Li ◽  
Kai Pan ◽  
Rong Li ◽  
Naiying Fan ◽  
...  

SrWO4:Ln3+ (Ln = Eu, Ce, and Tb) nanocrystals were successfully synthesized by a hydrothermal method, and were characterized by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy. The results indicated that the crystalline size of nanocrystals decreases with increasing Eu3+ concentrations and increases with increasing annealing temperature, gradually. The photoluminescence properties of SrWO4:Ln3+ were investigated in detail. In the emission spectra of SrWO4:Eu3+, the luminescence was dominated by 5D0 → 7F2 transition, indicating that Eu3+ occupied a site lacking inversion symmetry. The concentration quenching effect hardly occurs. In the excitation spectra of SrWO4:Eu3+ nanocrystals monitored at 619 nm, the most intense peak is centered at 467 nm when the Eu3+ concentration was less than 10%, while the most intense peak is centered at 396 nm when the Eu3+ concentration was 15%. In the normalized emission spectra of SrWO4:Ce3+/Tb3+ nanocrystals excited at 254 nm, the intensity ratio of the sharp emission peaks from Tb3+ ions to the broad emission band from Ce3+ ions increased with increasing Tb3+ concentration.


2014 ◽  
Vol 508 ◽  
pp. 26-29 ◽  
Author(s):  
Su Wen Li ◽  
Ming Yue

An efficient near-infrared (NIR) quantum cutting (QC) nanophospors with Ce3+, Yb3+ co-doped in YF3 had been prepared by hydrothermal method and characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), photoluminescence spectra and decay dynamics. The obtained nanorods were uniform and monodisperse. Under the excitation of 5d level of Ce3+, an intense NIR emission at 900 1100 nm was observed which match to the energy of Si band gap of Si - based solar cells. In the Ce3+, Yb3+ codoped YF3, the lifetime of Ce3+ decreases and the quantum efficiency (QE) increases with increasing Yb3+ concentration.


2016 ◽  
Vol 16 (4) ◽  
pp. 3494-3499 ◽  
Author(s):  
Xiaobing Luo ◽  
Jun Shen ◽  
He Huang ◽  
Lu Xu ◽  
Zhixiang Wang ◽  
...  

Efficient near-infrared (NIR) quantum cutting (QC) has been demonstrated in Yb3+ doped SrMoO4 phosphors synthesized by the high-temperature solid-state reaction method. The obtained SrMoO4:Yb3+ phosphors were characterized by X-ray diffraction (XRD), diffuse reflectance spectra, photoluminescence (PL) spectra and decay lifetime to understand the observed near-infrared quantum cutting phenomena. The XRD results show that all the prepared phosphors can be readily indexed to the pure tetragonal phase of SrMoO4 and exhibit good crystallinity. The experimental results showed that the strong visible molybdate (MoO2−24 emission around 493 nm and near-infrared (NIR) emission around 1000 nm from Yb3+(2F5/2 → 2F7/2) of SrMoO4:Yb3+ phosphors were observed under ultraviolet (290 nm) excitation. The Yb3+ concentration dependence of luminescent properties and lifetimes of both the visible and NIR emissions have also been investigated. The quenching concentration of Yb3+ ions approaches as high as 10 mol%. The cooperative energy transfer (CET) mechanism was also discussed in detail. The broadband NIR QC phosphors may possibly have potential application in enhancing the conversion efficiency of solar cells.


Sign in / Sign up

Export Citation Format

Share Document