The invention discloses mixed-valence-state
europium (Eu)
ion doped single-matrix color-adjustable fluorescent
powder and a preparation method thereof. An expression formula of the
chemical composition of the fluorescent
powder is Ca2-xEuxSiO2F2, wherein Eu is an active
ion, and is in +2 and +3 mixed-valence state; x is a
molar percentage coefficient accounted by the active
ion Eu relative to an
alkaline earth metal ion Ca, and x is more than or equal to 0.001 and less than or equal to 0.10; according to the fluorescent
powder, the active ion Eu is doped into a matrix Ca2SiO2F2, and under the condition that the matrix Ca2SiO2F2 can be effectively activated by near-
ultraviolet light, adjustable emission of a fluorescent powder material from
blue light to orange
red light can be achieved by changing the
doping concentration of the active ion Eu and adjusting the emission peak ratio of the
blue light of bivalent Eu ions to
red light of trivalent Eu ions; and specifically, with the increase of Eu
ion doping concentration, the relative strength of
red light emission of Eu<3+> can be increased, and the light emitting color of Ca2-xEuxSiO2F2 is gradually changed from blue to white, and is continuously changed to orange.