Synthesis And Properties Of Gallium Aluminate Luminescent Materials

Luminescent materials have received extensive attention because of their wide application fields,and they are the basis and hotspot of various researches.Not only in the well-known traditional lighting field,but also in the fields of new-type lighting,solar spectrum conversion,biological imaging,medical treatment,optical communication,and functional detection.You can change the type,concentration and matrix material of the activator to meet different application requirements.Rare earth ions are usually selected as the activator,but in recent years,transition metal ions have gradually attracted people's attention because of the advantages of low price,abundant reserves,and a wide excitation area.Compared with expensive rare earth ions,the transition metal ion doping is explored Miscellaneous luminescent materials are of great significance.In this paper,gallium aluminate co-doped with transition metal ions and rare earth ions and mono-doped with transition metal ions are synthesized by high-temperature solid-phase method.The specific work is as follows:?1?CaAl_12-xGa_xO₁₉:Mn⁴⁺?x=0–7?luminescent materials has been prepared and the effect of Ga³⁺instead of Al³⁺on structure,luminescence,fluorescence lifetime and quantum efficiency has been studied.Ga³⁺will replace the eight-coordinated Al³⁺,and the lattice change caused by the substitution may be the cause of the enhanced luminescence.CaAl_12-xGa_xO₁₉:Mn⁴⁺?x=0–7?has an excitation spectral range of250-550 nm and can be excited by ultraviolet-visible light.Under the excitation of466 nm,the emission wavelength is at 655nm,which can be matched with the plant pigment PR and is expected to become LED luminescent material for plant growth.When x=1,the luminous intensity of CaAl_12-xGa_xO₁₉:Mn⁴⁺?x=0–7?reaches maximum value.At this time,the quantum efficiency also reaches its maximum value.The internal and external quantum efficiencies are 82.1%and 67.6%,respectively.In addition,the influence of the doping concentration of Mn⁴⁺ions on CaAl₁₁GaO₁₉9 was studied.When the doping concentration of Mn⁴⁺was 0.002,the luminous intensity was the largest.?2?CaAl₆Ga₆O₁₉:Cr³⁺,Ln³⁺?Ln=Yb,Nd,Er?luminescent materials has been prepared and their luminous properties and energy transfer has been studied.As a sensitizer,Cr³⁺ions can absorb the photon energy from ultraviolet to visible light and transfer it to Ln³⁺for emission in the near infrared region.The maximum energy transfer efficiency of Cr³⁺-Yb³⁺,Cr³⁺-Nd³⁺,and Cr³⁺-Er³⁺are 25.84%,73.90%,and29.46%,respectively.CaAl₆Ga₆O₁₉:Cr³⁺,Ln³⁺?Ln=Yb,Nd,Er?luminescent materials may be become light conversion materials for silicon-based solar cells.?3?The CaAl₆Ga₆O₁₉:Mn⁴⁺luminescent material has been prepared and the effect of Mg²⁺as a charge compensator on the luminous intensity of CaAl₆Ga₆O₁₉:Mn⁴⁺has been studied.When the doping concentration of Mn⁴⁺is 0.005,the luminous intensity of CaAl₆Ga₆O₁₉:Mn⁴⁺is the strongest.When the doping concentration of Mg²⁺is 0.09,the luminous intensity of CaAl₆Ga₆O₁₉:Mn⁴⁺increases by 1.77 times.