Broadband Conversion And Collaborative Of Er³⁺/Yb³⁺、Er³⁺/Ho³⁺ Doped Material

With the rapid development of society, the excessive consumption of energywhich lead to the coal, oil, natural gas and other resources on earth quickly dried up.So, finding new renewable energy becomes the current urgent problems to be solved.Solar energy as a clean, pollution-free, the renewable energy, has arising muchattention. Therefore, the use of electric energy production by solar cells are aneffective way to solve the energy crisis. However, the photoelectric conversionefficiency of solar cells is still low. because the solar cells cannot make full use ofsunlight. Solar cells can only absorb sunlight in the visible, and near-ultraviolet of thehighest energy and near-infrared light of highest proportion of sunlight cannot beabsorbed. Consequently, in order to overcome this drawback of solar cells, peoplethought of using rare-earth photoluminescence material to go with sun light. Whichcan convert the light of unavailable into available for solar cells, so as to improve thephotoelectric conversion efficiency of solar cells. However, light conversion materialfor solar cells are also still has many shortcomings, we still need to improve theperformance of light conversion material.Firstly,Yb（Er）F3nanoparticles absorbed with ZnO sheet were prepared viatwo-step co-precipitation method followed with thermal oxidation. In theZnO/Yb（Er）F3composite phosphor, ZnO can efficiently absorb ultraviolet photons of250nm-380nm and transfer its absorbed photon energy to Er³⁺ions in fluorideparticles. A followed quantum cutting between Er³⁺-Yb³⁺couples in the fluoride takesplace, down-converting an absorbed ultraviolet photon into two photons of650nmand980nm radiations. The composite phosphor combines the wide wavelengthabsorption range and high absorption cross-section of ZnO with high quantum cuttingefficiency of Er³⁺-Yb³⁺co-doped fluoride, showing potential application in theenhancement of Si solar cell efficiency.Secondly, SiO₂–PbF₂–ErF₃–Ho₂O₃glass prepared by rapid cooling method. Weselect the445nm and980nm laser as excitation source as well as the808nm and980nm laser. The sample was excited by single excitation source and doubleexcitation source. Interestingly, by calculating the integrated intensity of its emission,we found that when sample is excited by double excitation source its red emissionintegrated intensity is much higher than that the sum excited by the two single excitation source. And the same result can be observed for the green emission. Webelieve that this is due to cross energy transfer occur between Er³⁺and Ho³⁺in thesample. It means a synergistic mechanism occurs when the glass ceramic is excited bydouble laser sources.