Near-infrared-luminescence bismuth-doped barium chloropentaborate crystal and preparation method thereof

The invention discloses a near-infrared-luminescence bismuth-doped barium chloropentaborate crystal and a preparation method thereof. The chemical formula of the bismuth-doped barium chloropentaborate crystal is Ba2(1-x)B5O9Cl:2*Bi, wherein 0.0001<=x<=0.10. The invention also discloses a method for preparing the bismuth-doped barium chloropentaborate crystal respectively by a high-temperature solid-phase method and a melt method. The high-temperature solid-phase method comprises the following steps: after grinding and evenly mixing a compound raw material containing barium, boron, chlorine and bismuth, prefiring, grinding and evenly mixing, firing at high temperature, and reacting the fired material at 800-100 DEG C in a reducing atmosphere. Compared with the existing rare-earth-doped material, the Ba2B5O9Cl:Bi crystal can absorb ultraviolet, visible and near-infrared spectral ranges, and has near-infrared luminescence within the band width of 800-1500nm; and the fluorescent full width at half maximum is greater than 200nm, and the fluorescence lifetime is longer than 30 microseconds.