Synthesis And Study Of Micro-Nano Spectra Converts With Broadband Absorption And NIR Emission

This work is focused on synthetizing novel spectra convert phosphors forharvesting C-Si cell eiffciency. We prepared micron YAB:Cr3+,Yb3+/Nd3+spectraconverts by high temperature solid state reaction, and we synthesized nano matrixY3AI5O12, Ce3+and Yb3+were introduced to prepare nano spectra convertsY3Al50i2+:Ce3，Yb3+，meanwhile higher transmittace and spectra convert film wasprepared with S1O2nanospheres. The prepared micron spectra converts has higherperformance than traditional spectra converts, and the reaction condition forpreparing nano spectra converts is more moderate than available technology, theprepared nano-materials disperse more evenly.In the second chapter, broadband absorption and high NIR emission spectraconverts YABrC^Yb3"^were synthesized by high temperature solid state reaction。The spectra converts has ultra-wide absorption band from350nm to750nm, andconvert the absorbed light to about983nm strong NIR light, it can be applied forharvesting c-Si based solar cell efifciency. The XRD revised date proved that Cr3—occupied Al3+sites, and we demonstrate that energy transfer occurir+ng from Cr3toYb3++. Th3++e replace of Y3with Gd, Bi3+and La3result in higher NIR emissionintensity. When the substitute ionic radius+exceeds Y3, the closer the radius to Y3+,the better emission intensity we will get, it has no effect when the substitute ionic++radius less than Y3+. We also introduced Nd3in YAB:Cr3,Yb3+to broaden the NIRPL bandwidth. Neither the improving near-infrared emission intensity nor wideningthe width of the near-infrared emission, are making the spectra convertsYAB^iC^^jYb3more suitable for enhance the c-Si based solar cell eiffciency, onceapplied to actual can greatly improve the photoelectric conversion efficiency of solar cells.In the third chapter, We mainly prepared by two SiC>2/Y3Al50i2:Ce3+，Yb3+nanocomposite films. In this section, we first use ethanol with ethylene diamine andethylene diamine with polyethylene glycol200as solvent, Y3AI5O12nano matrixmaterial were prepared at220°C and250°C. The particle size of nano-materials wereabout80nm and40nm respectively. Both solvent system have its advantages anddisadvantages. We also tried other solvent system to prepare Y3AI5O12nanomaterials.Also a seires of discussions were made on Y3AI5O12nano-materials into phase+conditions and morphology control. In the end, we introduced Ce3+and Yb3toprepare nano spectra converts Y33Al50i2:C+e，Yb3+. Two methods were prepared SiO]/Y3Al50i2+:Ce3，Yb3+nano composite iflms, the ifrst method for prepairng a layer ofY3Al50i2:Ce3+,Yb3+membrane with polyvinylpyrrolidone and a layer of Si02film,the second method uses SiCh wrapped Y3AI5012+:Ce3,Yb3+prepared SiCVY33Al50i2:C+e，Yb3+nano composite monolayer films, both methods result in thetransmittance increased by nearly4percent, while the UV and blue light is convertedto near-infrared light. Once applied on solar cell encapsulation glass surface wouldincrease the photoelectric conversion eiffciency.