Preparation of Red Phosphor Sr2Si5N8: Eu2+ by Pellet Method and Its Optical Characteristics

Red Sr2Si5N8: Eu2+ phosphor with excellent properties was successfully synthesized by pellet method, an effective synthesis technology presented in this work. The influence of reactive conditions such as pellet pressure, position of samples in carbon powder, and Eu2+ ion concentration on the properties of crystallinity, particle size, and the photoluminescence properties of Sr2Si5N8: Eu2+ phosphor were studied in detail. Our results show that the optimum preparation condition is 1500, 5 MPa pellet pressure, and the middle position in carbon powder. The phosphor has improved its efficiency under excitation of near UV and blue LEDs, and it emits red light at around 620 nm. In addition, red LEDs were successfully prepared by using Sr2Si5N8: Eu2+ phosphor combined with UV-chips with maximum luminous efficiency at 9.443 lm/W, when the molar concentration of Eu2+ ion reached 0.001.