Green fluorescent powder for white LED (light-emitting diode) use, its preparation method and application

The invention discloses green fluorescent powder Ca6Sr4-x (Si2O7)3Cl2: xEu for white LED use, its preparation method and application. The fluorescent powder is synthesized through a high temperature solid phase method under a reducing atmosphere with CaO, SiO2, CaCl2 and SrCO3 as raw materials, Eu2O3 as an activator and excess CaCl2 as a fluxing agent. Existing green fluorescent powder has low luminous efficiency when excited near a wavelength of 400nm, while the fluorescent powder disclosed in the invention can realize high efficiency excitation at an ultraviolet-near ultraviolet wavelength as well as high luminous efficiency. Therefore, the fluorescent powder of the invention can be used for preparing a white LED and a green LED that are excited by an ultraviolet-near ultraviolet (350-410nm) LED die. In addition, the fluorescent powder has low calcining temperature and simple preparation method, and can be promoted and applied in the fields of lighting and displaying, thus boasting substantial economic and social benefits.