Growth And Spectral Properties Of Rare Earth Doped Bi₄Si₃O₁₂ Crystal

Bismuth silicate(Bi₄Si₃O₁₂,BSO)is a famous excellent scintillator with short decay time and high radiation hardness.BSO crystal has the advantages of good photoelectric properties and excellent physical and chemical properties,and low cost.Furthermore,BSO crystal is a good host material for optical applications.Doping ions is one of the important ways to improve the performance of BSO crystal.Compared with other ions,rare earth ions have unique 4f electronic configuration and optical performance.The rare earth ions can emit light from ultraviolet to infrared region.In this paper,Ho-doped,Eu-doped,Sm-doped and Tb-doped Bi₄Si₃O₁₂2 crystals have been grown by the modified vertical Bridgman method.As-grown crystals were characterized by transmission spectra,excitation spectra,emission spectra and decay time.Bi₄Si₃O₁₂2 crystals doped with Ho,Eu,Sm or Tb have good uniformity and they have about80%transmittance in the range from 350 to 800 nm,with an absorption edge at 285 nm.They present the characteristic absorption peak of trivalent rare earth ions,corresponding to their respective 4f energy level transition.Ho³⁺,Eu³⁺,Sm³⁺and Tb³⁺doped BSO crystals have excitation band located in the range of 240-310 nm with the peak at 290 nm.The emission peak intensity of Ho³⁺,Sm³⁺and Tb³⁺doping BSO crystals at 480 nm is stronger than that of pure BSO crystal.However,the intensity of Eu³⁺doped BSO crystal at 480 nm is weaker than pure BSO crystal.Under excitation at 286 nm Ho³⁺,Sm³⁺and Tb³⁺doped BSO crystal can give green light emitting,but Eu³⁺doped BSO crystal emits white light.