Study Of Rare Earth Doped Yttrium Borate Two-dimensional Material Preparation And Down-conversion Luminescence Properties

This paper mainly studies down-conversion luminescence of rare earth doped yttrium borate materials, so as to improve its efficiency, by means of converting ultraviolet high-energy photons into near-infrared light which can’t be absorbed by silicon solar cell. Two-dimensional nano materials of yttrium borate have been prepared by solvothermal method, whose luminescent property and structure are influenced by annealing temperature. Finally different kinds of rare earth ions doped have themselves especial luminescence.YBO3two-dimensional nano materials have been prepared by solvothermal method, according to the following conditions:CA=0.125M、NB:NRE=4、pH=8. When other reaction conditions are indentical, micro-flowers are self-assembly by nanosheets, and luminescent intensity of samples annealed at900℃also will increase, as the solute concentration increases.To luminescence of YBO3:Ce3+,Yb3+sample, Subsequent thermal treatment plays a decisive role. When annealing temperature is higher than600℃, there is BO4group in the materials, and Vis and NIR emission of samples is obvious under the excitation of360nm. The higher annealing temperatures are, the stronger the luminescence of the sample is. To the unannealed sample, Vis emission is evident, because of existence of N-H bond.Studying luminescence of different kinds of RE-doped YBO3phosphors works out the following results:To Ce3+doped sample, when Ce3+doped concentration is greater than1%, the luminescent intensity decreases; To Tb3+doped sample, when Tb3+doped concentration is greater than1%, the light at470nm disappears because this is because of cross-relaxation between5D3-5D4and7F6-7F0; To Ce3+-Tb3+doped sample and Ce3+-Yb3+doped sample, energy transfer of Ce3+�'Tb3+is phonon auxiliary mechanism, and energy transfer of Ce3+�'Tb3+is Cooperative theory of DC; To Ce3+-Tb3+-Yb3+doped sample,Tb3+-doped will weaken NIR emission intensity of Yb3+.