Ultra-narrow-band purple light fluorescent powder as well as preparation method and application thereof

The chemical general formula of the ultra-narrow-band purple light fluorescent powder is A2M (PO3) 4: zEu < 2 + >, A is one or more of Na and K, and M is one or more of Ca, Sr and Ba; the ultra-narrow band means that the full width at half maximum of the emission spectrum of the fluorescent powder is lower than 25nm. The invention also discloses a preparation method of the ultra-narrow-band purple light fluorescent powder, which comprises the following steps: carrying out ball milling on raw materials, slowly pre-calcining, carrying out multi-stage heat preservation, finally heating to 200-350 DEG C, cooling and grinding; and finally, synthesizing at 550-700 DEG C in a reducing atmosphere, cooling and grinding. The invention further discloses application of the ultra-narrow-band purple light fluorescent powder in display devices and temperature sensing. The obtained fluorescent powder emits ultra-narrow-band purple light under excitation of near ultraviolet light, and is high in color purity, high in luminous