Zhiguo Zhang

Harbin Institute of Technology, Charbin, Heilongjiang Sheng, China

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Publications (91)252.5 Total impact

  • Yuan Zhou · Feng Qin · Yangdong Zheng · Zhiguo Zhang · Wenwu Cao
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    ABSTRACT: A thermometry method based on the ratio between the valley intensity formed by fluorescence peak overlap and the peak fluorescence intensity has been developed. Excited by a 405 nm laser, the valley to peak ratio (VPR) of the emissions originating from D<sub>0</sub>5 to F<sub>2</sub>7 Stark sublevels in Eu<sup>3+</sup>-doped CaWO<sub>4</sub> shows a monotonic change with temperature. Spectrum analysis indicates that this monotonic increase is caused by the homogeneous broadening of the spectral lines as the temperature increases. The relative sensitivity S<sub>r</sub> is in the magnitude of 10<sup>-4</sup> K<sup>-1</sup> in the experimental temperature range of 303-573 K.
    Optics Letters 09/2015; 40(19):4544-4547. DOI:10.1364/OL.40.004544 · 3.29 Impact Factor
  • Peng Wang · Feng Qin · Zhiguo Zhang · Wenwu Cao
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    ABSTRACT: The lack of accurate and robust photodynamic therapy dosimetry is one of the obstacles for the widespread clinical applications. In this study, we propose a methodology to monitor the production of reactive oxygen species in real-time using the phosphorescent spectra of metalloporphyrin based photosensitizer. The correlation among the phosphorescence intensity, the <sup>1</sup>O<sub>2</sub> quantum yield (Φ<sub>Δ</sub>) and the oxygen concentration [O<sub>2</sub>] was established. A method of determining Φ<sub>Δ</sub> with different [O<sub>2</sub>] was studied based on comparative spectrophotometry, and the quantum yield Φ<sub>Δ</sub> of gadolinium metalated hematoporphyrin mono ether (Gd-HMME) in methanol was determined for different [O<sub>2</sub>]. With our method, both [O<sub>2</sub>] and Φ<sub>Δ</sub> could be monitored simultaneously using the phosphorescence spectra. The photochemical reactions in a liquid phantom composed of Gd-HMME and <sup>1</sup>O<sub>2</sub> capture 1,3-diphenylisobenzofuran (DPBF) were correlated using the kinetics equations of singlet oxygen generation and reaction. Using our method, the <sup>1</sup>O<sub>2</sub> quantum yield becomes observable and the <sup>1</sup>O<sub>2</sub> dose rate could be calculated by the product of photosensitizer absorption and its <sup>1</sup>O<sub>2</sub> quantum yield. Moreover, this <sup>1</sup>O<sub>2</sub> dosimetry could be observed by spectral imaging intuitively without complex analysis, and is especially suitable for precise customized photodynamic treatment.
    Optics Express 09/2015; 23(18):22991-23003. DOI:10.1364/OE.23.022991 · 3.49 Impact Factor
  • Huimin Zhao · Lixin Zang · Lin Wang · Feng Qin · Zhiguo Zhang · Wenwu Cao
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    ABSTRACT: A fluorescence–phosphorescence ratiometric oxygen sensing system based on gadolinium labeled hematoporphyrin monomethyl ether (Gd-HMME) and filter paper was developed. A compact and simple measurement system was constructed utilizing fiber optoelectronic sensing device. Optical parameter (OP) was defined as the ratio of filter paper background fluorescence to oxygen sensitive Gd-HMME phosphorescence. We demonstrate that the OP is independent of excitation intensity in this ratiometric method. The measured results of oxygen concentration were calibrated and displayed by a Labview-based software. The fluctuation is about 0.1% for a wide range of oxygen concentration above 10% and much less than 0.1% for oxygen concentrations lower than 3%. A detection limit of 0.01% was achieved. The response time was determined to be about 4 s. These results indicate that the system we have developed can be used for oxygen detection in the whole range and is especially accurate for very low oxygen concentrations.
    Sensors and Actuators B Chemical 08/2015; 215. DOI:10.1016/j.snb.2015.04.002 · 4.10 Impact Factor
  • Huimin Zhao · Lixin Zang · Hua Zhao · Feng Qin · Zhongwei Li · Zhiguo Zhang · Wenwu Cao
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    ABSTRACT: The spin-orbit coupling mechanism was generally used to explain heavy atom effect induced room temperature phosphorescence (RTP). Here, we demonstrate that the mechanism of RTP induced by Gd3+ from hematoporphyrin monomethyl ether (HMME) is due to the mixing of singlet (S) and triplet (T) states. The spin-forbidden transition between S and T states was partly allowed due to the states mixing, as indicted by the direct absorption corresponding to transition from S0 to T1, which was observed for the first time from RTP. The quantum yield of T1 was determined to be 0.80 and the percent of each energy transfer process was determined. While there is no non-radiative relaxation from HMME to Gd3+ because of the large energy gap between the excited and ground states of Gd3+. The special energy level of Gd3+ as well as the states mixing between S and T states produced the strong phosphorescence emission. The population and deactivation of triplet states in heavy atom induced RTP can be used to analyze the mechanism of phosphorescent emission.
    The Journal of Physical Chemistry C 04/2015; 119(19):150428115432005. DOI:10.1021/acs.jpcc.5b00328 · 4.77 Impact Factor
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    Wei Tang · Ye Sun · Miao Yu · Xiao Liu · Yongqi Yin · Bin Yang · Limei Zheng · Feng Qin · Zhiguo Zhang · Wenwu Cao
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    ABSTRACT: Single-phase SrTiO3:mPr3+(m=0.01-0.1) nanoparticles have been synthesized by a hydrothermal method. Different from reported Pr3+-based phosphors which were all dominated by red emissions, considerably strong and overwhelming blue-green emission centered at 491 nm has been achieved together with minor green and red emissions. The absolute and relative intensities of these emissions can be modified by Pr3+ concentrations and annealing temperatures in a controlled manner, giving rise to varied emission colors. In particular, owing to the appropriate combination of the blue to red emissions, desirable white-light emission has been realized from the as-grown SrTiO3:0.01Pr3+ and the annealed SrTiO3:0.06Pr3+ samples at 350 oC with CIE chromaticity coordinates of (0.33, 0.35) and (0.35, 0.37) and a correlated color temperature of 5601 K and 4883 K, respectively, indicating the promising application potential of SrTiO3:Pr3+ as single-phase phosphors for white light-emitting-diodes. This work may provide a fresh route to acquire white emission from a single-composition phosphor.
    RSC Advances 03/2015; 5(35). DOI:10.1039/C4RA16757K · 3.84 Impact Factor
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    ABSTRACT: Oxygen sensing properties of a luminescent material gadolinium labeled hematoporphyrin monomethyl ether (Gd-HMME) based on filter paper were studied. Photoluminescence of Gd-HMME at 712 nm was confirmed to be phosphorescence by a time-resolved spectroscopic analysis and its dependence on oxygen. Quantum yield of the phosphorescence was determined to be 0.014 in air saturated methanol solution (λexc = 532 nm). A linear range was found from 10% to 100% oxygen concentration in Stern–Volmer plots for Gd-HMME based on filter paper. Fast response time, recovery time (t↓, 0.4 ± 0.2 s; t↑, 1.4 ± 0.2 s) and high photostability were achieved. Our results indicate that Gd-HMME is a promising indicator for optical oxygen sensing.
    Sensors and Actuators B Chemical 01/2015; 206:351–356. DOI:10.1016/j.snb.2014.09.070 · 4.10 Impact Factor
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    ABSTRACT: Ultrasound combined with endogenous protoporphyrin IX derived from 5-aminolevulinic acid (ALA-SDT) is known to induce apoptosis in multiple cancer cells and macrophages. Persistent retention of macrophages in the plaque has been implicated in the pathophysiology and progression of atherosclerosis. Here we investigated the effects of inhibition of voltage-dependent anion channel 1 (VDAC1) on ALA-SDT-induced THP-1 macrophages apoptosis. Cells were pre-treated with VDAC1 inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) disodium salt for 1 h or downregulated VDAC1 expression by small interfering RNA and exposed to ultrasound. Cell viability was assessed by MTT assay, and cell apoptosis along with necrosis was evaluated by Hoechst 33342/propidium iodide staining and flow cytometry. Levels of cytochrome c release was assessed by confocal microscope and Western blot. The levels of full length caspases, caspase activation, and VDAC isoforms were analyzed by Western blot. Intracellular reactive oxygen species generation, mitochondrial membrane permeability, and intracellular Ca(2+) [Ca(2+)]i levels were measured with fluorescent probes. We confirmed that the pharmacological inhibition of VDAC1 by DIDS notably prevented ALA-SDT-induced cell apoptosis in THP-1 macrophages. Additionally, DIDS significantly inhibited intracellular ROS generation and apoptotic biochemical changes such as inner mitochondrial membrane permeabilization, loss of mitochondrial membrane potential, cytochrome c release and activation of caspase-3 and caspase-9. Moreover, ALA-SDT elevated the [Ca(2+)]i levels and it was also notably reduced by DIDS. Furthermore, both of intracellular ROS generation and cell apoptosis were predominately inhibited by Ca(2+) chelating reagent BAPTA-AM. Intriguingly, ALA-treatment markedly augmented VDAC1 protein levels exclusively, and the downregulation of VDAC1 expression by specific siRNA also significantly abolished cell apoptosis. Altogether, these results suggest that VDAC1 plays a crucial role in ALA-SDT-induced THP-1 macrophages apoptosis, and targeting VDAC1 is a potential way regulating macrophages apoptosis, a finding that may be relevant to therapeutic strategies against atherosclerosis.
    APOPTOSIS 10/2014; 19(12). DOI:10.1007/s10495-014-1045-5 · 3.69 Impact Factor
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    ABSTRACT: A special core/shell/shell structured NaYF4/ NaYF4:Yb3+,Er3+/ NaYF4 (CSS) nanocrystal was designed to ensure each luminescence center on the emitting shell having the same surroundings, which includes a support core NaYF4 nanoparticle in the center coated by a thin emitting shell NaYF4:Yb3+,Er3+ and another NaYF4 shell with adjustable thickness as the outer shielding shell. Green upconversion fluorescence intensity Ig(d) of CSS nanoparticles shows exponential relationship with the thickness d of the shielding shell. When d decreased to 0, Ig(0) decreased ~356 times as compared with Ig(∞) due to the drastic fluorescence quenching of rare earth luminescence centers from surroundings. Practically, the severe effect of surroundings can be eliminated ~ 90% by coating ~4 nm- thick NaYF4 shielding shell.
    CrystEngComm 09/2014; 16(43). DOI:10.1039/C4CE01441C · 4.03 Impact Factor
  • Wei Xu · Qiutong Song · Longjiang Zheng · Zhiguo Zhang · Wenwu Cao
  • Wei Xu · Qiutong Song · Longjiang Zheng · Zhiguo Zhang · Wenwu Cao
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    ABSTRACT: Under a 980 nm diode laser excitation, the near-infrared (NIR) emissions from Nd3+:F7/24, F5/24, and F3/24 states in Nd3+/Yb3+ codoped CaWO4 powder were studied at temperatures ranging from 303 to 873 K. As the temperature increased, the NIR luminescence intensity was significantly enhanced and nearly 190-fold enhancement was achieved at 873 K compared with that at 303 K. By using the fluorescence intensity ratio technique, the thermometry behaviors through the NIR emissions were investigated. The results illustrate that the sensitivity and the accuracy achieved here are much higher than temperature sensors based on other rare earth ion doped materials.
    Optics Letters 08/2014; 39(16). DOI:10.1364/OL.39.004635 · 3.29 Impact Factor
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    Jia Yu · Qiang Gao · Zhiguo Zhang
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    ABSTRACT: One direct and efficient method to improve the sensitivity of infrared gas sensors is to increase the optical path length of gas cells according to Beer-Lambert Law. In this paper, cubic shaped cavities with high reflected inner coating as novel long path absorption cells for infrared gas sensing were developed. The effective optical path length (EOPL) for a single cubic cavity and tandem cubic cavities were investigated based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) measuring oxygen P11 line at 763 nm. The law of EOPL of a diffuse cubic cavity in relation with the reflectivity of the coating, the port fraction and side length of the cavity was obtained. Experimental results manifested an increase of EOPL for tandem diffuse cubic cavities as the decrease of port fraction of the connecting aperture f', and the EOPL equaled to the sum of that of two single cubic cavities at f'<0.01. The EOPL spectra at infrared wavelength range for different inner coatings including high diffuse coatings and high reflected metallic thin film coatings were deduced.
    Infrared Sensors, Devices, and Applications IV, SPIE; 08/2014
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    Qiang Gao · Jia Yu · Yungang Zhang · Zhiguo Zhang · Wenwu Cao
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    ABSTRACT: A precise method for the measurement of diffuse reflectance by using gas absorption spectroscopy technique with an integrating sphere is demonstrated. A quantitative relationship between the diffuse reflectance and the gas absorption spectrum is formulated, which has been further validated by experiments. The precision of the reflectivity measurement depends on the diameter and port fraction of the integrating sphere as well as gas concentration, and it increases linearly with the magnitude of the reflectivity. A high precision of 0.005% was achieved at the reflectivity of 0.98844(5).
    Sensors and Actuators B Chemical 06/2014; 196:147–150. DOI:10.1016/j.snb.2014.02.010 · 4.10 Impact Factor
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    ABSTRACT: Background: In advanced atherosclerosis, chronic endoplasmic reticulum (ER) stress induces foam cells apoptosis and generates inflammatory reactions. Methods: THP-1 macrophage-derived foam cells (FC) were incubated with 1 mM 5-aminolevulinic acid (ALA). After ALA mediated sonodynamic therapy (ALA-SDT), apoptosis of FC was assayed by Annexin V-PI staining. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential were detected by staining with CellROX® Green Reagent and jc-1. Pretreatment of FC with N-acetylcysteine (NAC), Z-VAD-FMK or 4-phenylbutyrate (4-PBA), mitochondria apoptotic pathway associated proteins and C/EBP-homologous (CHOP) expressions were assayed by wertern blotting. Results: Burst of apoptosis of FC was observed at 5-hour after ALA-SDT with 6-hour incubation of ALA and 0.4 W/cm(2) ultrasound. After ALA-SDT, intracellular ROS level increased and mitochondrial membrane potential collapsed. Translocations of cytochrome c from mitochondria into cytosol and Bax from cytosol into mitochondria, cleaved caspase 9, cleaved caspase 3, upregulation of CHOP, as well as downregulation of Bcl-2 after ALA-SDT were detected, which could be suppressed by NAC. Activation of mitochondria-caspase pathway could not be inhibited by 4-PBA. Cleaved caspase 9 and caspase 3 as well as apoptosis induced by ALA-SDT could be inhibited by Z-VAD-FMK. Conclusion: The mitochondria-caspase pathway is predominant in the apoptosis of FC induced by ALA-SDT though ER stress participates in. © 2014 S. Karger AG, Basel.
    Cellular Physiology and Biochemistry 05/2014; 33(6):1789-1801. DOI:10.1159/000362958 · 2.88 Impact Factor
  • Lifeng Liu · Yuanjian Song · Limin Ma · Lixin Zang · Lili Tao · Zhiguo Zhang · Jiwu Han
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    ABSTRACT: Photodynamic therapy (PDT) is considered a promising new strategy for liver cancer treatment. Three elements of PDT-optical output power, irradiation time, and photosensitizer concentration-play important roles in promoting cell death. This research aimed to characterize the effects of hematoporphyrin monomethyl ether (HMME)-based PDT on hepatocellular carcinoma cells HepG2 and thus elucidate the relationship between cell death and the three elements mentioned earlier. Furthermore, in this study, we present a parameter that represents the cumulative effects of these elements. The accumulation of HMME in HepG2 cells was observed by fluorescence microscopy. The absorption spectrum of HMME was detected using fluorescence spectral analysis. The viability of the treated cells was determined using the MTT assay, and cell apoptosis was evaluated using flow cytometry. We found that the fluorescence intensity was positively correlated with the incubation time for up to 2 h. The cell growth inhibition rate was significantly high and gradually increased with increasing concentrations of HMME or increasing light intensity, which was calculated as optical output power × irradiation time. Further analysis revealed an e-exponential decay of the cell survival rate to the product of the HMME concentration and the light intensity. We defined the product as parameter B (B = optical output power × irradiation time × HMME concentration). Similarly, the rate of cell apoptosis showed roughly e-exponential growth to parameter B. In conclusion, HMME-mediated PDT can significantly kill HepG2 cells, and the killing effect was related to the cumulative effects of the optical output power, the irradiation time, and the HMME concentration. Therefore, the newly defined parameter B, as a comprehensive physical quantity, may be of great significance for the regulation of light and photosensitizer according to patient-specific conditions in clinical practice.
    Lasers in Medical Science 05/2014; 29(5). DOI:10.1007/s10103-014-1583-7 · 2.49 Impact Factor
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    ABSTRACT: Photodynamic therapy for deep-lying lesions needs an appropriate imaging modality, precise evaluation of tissue oxygen and an effective photosensitizer. Gadolinium based metalloporphyrins Gd(III)-HMME is proposed in this study as a potential multifunctional theranostic agent, as photosensitizer, ratiometric oxygen sensor and MRI contrast agent. The time resolved spectroscopy revealed the luminescence peak of Gd(III)-HMME at 710 and 779 nm with a lifetime of 64 μs in oxygen-free methanol to be phosphorescent. This phosphorescence is strongly dependent on dissolved oxygen concentration. Its intensity in oxygen saturated methanol solution is 21% of that in deoxygenated solution. The singlet oxygen quantum yields Φ<sub>Δ</sub> of HMME and Gd(III)-HMME in air saturated methanol solution were determined to be 0.79 and 0.40 respectively using comparative spectra method. These phenomena indicate that the oxygen sensibility and production of singlet oxygen of Gd(III)-HMME can fulfill the requirement of PDT treatment.
    Optics Express 02/2014; 22(3):2414-22. DOI:10.1364/OE.22.002414 · 3.49 Impact Factor
  • Yunfei Qu · Rui Wang · Zhiguo Zhang · Liang Liu · Jinchao Sun · Ye Tao
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    ABSTRACT: Ho3+/Yb3+/Tm3+ codoped 12CaO·7Al2O3 (C12A7) polycrystals exhibiting upconversion white-light under 980 nm excitation have been successfully synthesized by high temperature solid-state reaction method. An orthogonal experiment is designed for finding out the effects of the rare earth ions concentrations on the intensity of white light. In order to realize the generating of white-light, the feasible solution is to increase the concentration of Ho3+ and decrease the Tm3+ concentration. CIE coordinate of C12A7:0.5 mol% Ho3+/4.0 mol% Yb3+/0.7 mol%Tm3+ sample at 980 nm excitation under 800 mW is (0.32, 0.34), which is very close to the white emission center (0.33, 0.33). As the pump powers increasing, the tendency of color coordinates is toward the blue region. The pump dependence suggests that the blue upconversion emissions are populated by a three-photon process, the green emissions are a two-photon process, the red emissions are a combination of two and three photons processes. Studies on the upconversion mechanism show that the blue and green emissions are attributed to Tm3+:1G4·3H6 and Ho3+:5F4/5S2·5I8, respectively. The red emissions include two parts: Tm3+:1G4·3F4 and Ho3+:5F5·5I8.
    Science of Advanced Materials 02/2014; 6(2):343-348. DOI:10.1166/sam.2014.1721 · 2.60 Impact Factor
  • Lili Xing · Yanling Xu · Rui Wang · Wei Xu · Zhiguo Zhang
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    ABSTRACT: Under 980 nm excitation, upconversion emissions originating from F3<sub>2,3</sub>→H3<sub>6</sub> and H3<sub>4</sub>→H3<sub>6</sub> transitions of Tm<sup>3+</sup> ion in LiNbO<sub>3</sub> single crystal were studied as a function of temperature in the range of 323-773 K. The F3<sub>2,3</sub> and H3<sub>4</sub> levels of Tm<sup>3+</sup> ion are confirmed to be thermally coupled levels. By using fluorescence intensity ratio technique, the sensitivity of optical temperature sensor achieved in our work is higher than other reported temperature sensors. Additionally, this optical temperature sensor is well suited to high operating temperature. Tm<sup>3+</sup>/Yb<sup>3+</sup> codoped LiNbO<sub>3</sub> is a promising candidate for fabricating excellent optical temperature sensors.
    Optics Letters 02/2014; 39(3):454-7. · 3.29 Impact Factor
  • Lili Xing · Yanling Xu · Rui Wang · Wei Xu · Zhiguo Zhang
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    ABSTRACT: Under 980 nm excitation, upconversion emissions originating from F32,3→H36 and H34→H36 transitions of Tm3+ ion in LiNbO3 single crystal were studied as a function of temperature in the range of 323–773 K. The F32,3 and H34 levels of Tm3+ ion are confirmed to be thermally coupled levels. By using fluorescence intensity ratio technique, the sensitivity of optical temperature sensor achieved in our work is higher than other reported temperature sensors. Additionally, this optical temperature sensor is well suited to high operating temperature. Tm3+/Yb3+ codoped LiNbO3 is a promising candidate for fabricating excellent optical temperature sensors.
    Optics Letters 01/2014; 39(3). DOI:10.1364/OL.39.000454 · 3.29 Impact Factor
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    ABSTRACT: To develop a fluorescent bioprobe for high-contrast deep tissue fluorescence imaging, monochromatic 800 nm upconversion emissions based on NaYF4: Yb3+, Tm3+ upconversion nanoparticles are investigated. The ratio of I800 to I470, which is used to describe the monochromaticity, showing exponential growth with the increase of Tm3+ doping concentration in NaYF4: Yb3+, Tm3+ nanoparticles, can reach as high as 757 at 4% Tm3+. At such a doping level, the absolute quantum efficiency can reach 3.9 × 10–3 as measured by a calibrated integrating sphere, which is sufficient for fluorescence imaging. High-contrast fluorescence phantom imaging was obtained by adjusting monochromaticity of 800 nm upconversion emission under the excitation of a 980 nm diode laser.
    The Journal of Physical Chemistry C 01/2014; 118(5):2820–2825. DOI:10.1021/jp410993a · 4.77 Impact Factor
  • Qianqian Duan · Feng Qin · Hua Zhao · Zhiguo Zhang · Wenwu Cao
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    ABSTRACT: The absolute quantum cutting efficiency of Tb3+-Yb3+ co-doped glass was quantitatively measured by an integrating sphere detection system, which is independent of the excitation power. As the Yb3+ concentration increases, the near infrared quantum efficiency exhibited an exponential growth with an upper limit of 13.5%, but the visible light efficiency was reduced rapidly. As a result, the total quantum efficiency monotonically decreases rather than increases as theory predicted. In fact, the absolute quantum efficiency was far less than the theoretical value due to the low radiative efficiency of Tb3+ (<61%) and significant cross-relaxation nonradiative loss between Yb3+ ions.
    Journal of Applied Physics 12/2013; 114(21):213513-213513-4. DOI:10.1063/1.4838435 · 2.18 Impact Factor

Publication Stats

890 Citations
252.50 Total Impact Points


  • 2006–2015
    • Harbin Institute of Technology
      • • Institute of Condensed Matter Science and Technology
      • • Department of Physics
      Charbin, Heilongjiang Sheng, China
  • 2007
    • Lund University
      • Department of Physics
      Lund, Skåne, Sweden