Regulation Of Bismuth Ions Valence State And Luminescent Properties In Bismuth Doped Oxide Crystals

Bismuth-doped near-infrared luminescence materials have attracted much attention due to their unique ultra-broadband luminescence properties.The luminescence properties of bismuth doped materials are closely related to the valence state of bismuth ions.In this paper,bismuth doped oxide crystals containing different alkaline earth metal ions were selected as the research object.?1?The valence state regulation and luminescence properties of Bi ions in the Sr₃Ga₄O₉:Bi crystal were studied.Under the condition of air preparation,the valence state of bismuth ion is+3.A tunable luminescence peaking at 530 nm and 680 nm can be produced under the excitation of 240-400 nm light,and Sr₃Ga₄O₉:Bi crystal can obtain long afterglow luminescence and mechanoluminescence peaking at 530 nm and 680 nm,afterglow can last for 6.5 h.The luminescence of low bismuth ion was not found after the reduction atmosphere treatment;?2?The valence state regulation and luminescence properties of Bi ions in the Ba₂Y₅B₅O₁₇:Bi crystal were studied.Under the condition of air preparation,the valence state of bismuth ion is+3.Ba₂Y₅B₅O₁₇:Bi can be used as a blue light phosphor powder with high absorption efficiency in the range of 360-390 nm,which is well matched with the near-ultraviolet light-emitting diode chip.We combined phosphor powder with LED chip?emission peak at 370 nm,20 m A?to make an LED device.The demonstration experiment results show that Ba₂Y₅B₅O₁₇:Bi has a potential application prospect in WLEDs.The luminescence of low bismuth ion was not found after the reduction atmosphere treatment;?3?The valence state regulation and luminescence properties of Bi ions in the Sr₃Y₂Ge₃O₁₂:Bi crystal were studied.Under the condition of air preparation,the valence state of bismuth ion is+3.Sr₃Y₂Ge₃O₁₂:Bi crystal can produce near ultraviolet-indigo-near infrared long persistence and mechanoluminescence,light emitting peak position is 350 nm,460 nm and 720 nm,respectively,afterglow can last for 6 h,and the near infrared region light emitting is from the matrix.The luminescence of low bismuth ion was not found after the reduction atmosphere treatment;?4?The valence state regulation and luminescence properties of Bi ions in the Sr₂B₅O₉Cl:Bi crystal were studied.Under the condition of air preparation,the valence state of bismuth ion is+3.When the atmosphere was nitrogen/hydrogen,bismuth ions gradually to near-infrared region?600-1600 nm?.The red luminous peak is located at 650 nm,which is derived from Bi²⁺.The luminous peak in the near infrared region is located at 780 nm,990 nm and 1280 nm,which is derived from lower valance state Bi⁺and Bi⁰.In this experiment,we achieved the regulation of bismuth ion valence state in oxide crystal by means of special structure matrix and atmosphere induction.