| The luminescent mechanism of Up-conversion luminescent materials follows theanti-Stokes law, which is opposite to the luminescent mechanism of the traditionalsolar cell. That is to say it can absorb low frequency light and excite higherfrequencies light. Since its discovery, the Up-conversion luminescent material hasbeen widely used in indicator lamp, emittercolor display, night vision system,up-conversion laser, biomedical, sensors, and other fields like national defense.Because of doped with rare earth ions work as luminescence centers and thenano-materials with large specific surface area, wich will influence the conversionluminescence of Up-conversion nano-materials, even cause quenching fluorescence.The adoption of core-shell structure design is an effective way to solve theseproblems, But there is an effective way to solve this problem, that is core-shellstructure.Y2O3:Eu3+/Yb3+nano-materials are synthesized by Pechini-type sol-gel methodand Y2O3:Eu3+/Yb3+@SiO2core-shell structure is prepared by St ber method in thispaper. The best optimum experimental parameters have been found throughresearching on the relationship between the effects of complexant agentconcentration, PH value, drying temperature, sintering temperature and the crystalstructure of nano-particles. The material is characterized through laser particle sizeanalyzer, XRD, absorption spectrum, emission spectrum, Fourier transform infraredspectroscopy and other testing methods. The luminescence mechanism of theUp-conversion material was studied by the ion (Y3+, Yb3+, Eu3+) energy leveldiagram and with the double logarithmic curve of the luminescence intensity andexcitation power.The XRD results show that when the molar concentration of citric acid is4mol/L, the crystal shows will have a relatively better good crystallinity, doped Yb3+and Eu3+ion don’ change he c^al c e of Y2O3, SiO2cladding doe n’change crystal structure of Y2O3, either. The Absorption spectrum shows thatY2O3:Eu3+/Yb3+nano-particles can be able to absorb the900~1000nm near-infraredlight, among which a strongest adsorption peak shows at980nm. Emissionspectrum shows that When excited by980nm, the Y2O3:Eu3+/Yb3+nano-particlesare able to emit the light with a wave from580nm to635nm light, among which611nm shows a strongest emission peak, which suitable to be applied in solar cellfor solar to use. FT-IR test indicates that the SiO2successfully coatings on thesurface of Y2O3:Eu3+/Yb3+nano-particles Surface.Also, in this paper Y2O3:Eu3+/Yb3+@SiO2Up-conversion-nanometers-material also is applied in amorphous silicon thin film cell, and measure its J-Vcharacteristics., experimental results show that the application of Up-conversionmaterial is able to increase the short-circuit current and cut down the open-circuitvoltage of the solar cell, which will increase its conversion efficiency ofphotoelectric. |
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