The invention discloses a near
infrared up-conversion long
afterglow luminescent material and a preparation method thereof. The preparation method comprises the following steps: (1) weighing raw materials, and evenly mixing
raw material powder, wherein the raw materials comprises a
raw material A, a
raw material B, a raw material C, and a raw material D, the raw material A is
chromium oxides or corresponding salts, the raw material B is oxides of
erbium or
thulium or corresponding salts, the raw material C is
ytterbium oxides or corresponding salts, and the raw material D is oxides of
zinc,
gallium / aluminum, or
germanium /
tin or corresponding salts; and (2) pressing and moulding mixed
powder obtained in the step (1) to obtain a blank sample; (3)
solid-phase
sintering the blank sample obtained in the step (2) at a high temperature; and (4) cooling the
sintering product to obtain the target material. A high temperature
solid phase method is adopted, the
prepared material, which is doped by Cr<3+> and Er<3+> / Tm<3+> and takes Yb<3+> as the sensitizing agent, has a near
infrared excited up-conversion
luminescence function and a super long time
afterglow performance and can be used as a high performance functional material applied to related fields.