The invention discloses a LED
plant growth warm white fluorescent
powder and a preparation method thereof. The
chemical formula of the fluorescent
powder is RM<x>Y<y> (WO<4>)<3y / 2> (PO<4>)< (1 + 2X) / 3>: aEu<3+>, bMn<4+>, wherein R is one of Li, Rb, Cs or In, M is one of Ca, Sr, Ba or Mg, 0.1 < = x < = 0.75, 0.2 < = y < = 0.55, and 0.1 < = a < 0.8, 0.3<=b<2. The method comprises steps:
grinding ina
mortar, mixing R2CO3 and M3(PO3)2, dropwise adding a
mixed solution of R2CO3 and M3(PO3)2, adding RMnO4, stirring, taking an obtained precipitate for
hydrothermal reaction, and mixing with Eu2O3 toobtain a precursor
powder; carrying out high-temperature firing in a
reducing atmosphere, adopting an alkaline-earth
metal and Y co-doped mixed
tungsten phosphate system as a matrix material, codopingEu < 3 + > and Mn < 4 + > to serve as activated light-emitting particles, transferring excitation energy from R3 to sensitized Mn < 4 + >, carrying out gradient
temperature control firing treatment after a precursor is prepared through a
hydrothermal synthesis method, so that activity and light-emitting efficiency are improved, and
concentration quenching effect is overcome. The problems of insufficient stability and deliquescence
pollution are avoided, and the requirements of red fluorescent powder for growth of warm white LED plants are met.