The luminescence properties of Sr 2-1.5x-1.5y P 2 O 7 :xDy 3+ ,yCe 3+ phosphor for near-UV-based white LEDs synthesized by a chemical co-precipitation method

• Published in: Luminescence (Chichester, England) England), 2017-12, Vol.32 (8), p.1582-1592
• Main Authors: Liu, Sha-Sha, Zhu, Da-Chuan, Wang, Jin-Shan, Zhao, Cong, Han, Tao
• Format: Article
• Language: English
• ISSN: 1522-7235; 1522-7243
• DOI: 10.1002/bio.3363

A series of Sr P O :Dy , Sr P O :Ce and Sr P O :Dy ,Ce phosphors was synthesized via the one-step calcination process for the precursors prepared by co-precipitation methods. The phases, morphology, quantum efficiency and photoluminescence properties of the obtained phosphors were characterized systematically. These results show that the near-spherical particles prepared through calcining the precursors by means of ammonium dibasic phosphate co-precipitation (method 3) have the smallest particle size and strongest emission intensity among the three methods in the paper. With Dy concentration increasing in Sr P O :Dy phosphors, the luminescence intensity first increases, reaches maximum, and then decreases. A similar trend was followed by Sr P O :Ce with Ce concentration increasing. A successful attempt was made to initiate the energy transfer mechanism from Ce to Dy in the host lattice and an overlap between the emission band of Ce and the excitation band of Dy indicated that the Ce  → Dy energy transfer may indeed exist. It is clear that the photoluminescence intensity of Dy as well as the quantum efficiency of the phosphor can be enhanced markedly by co-doping Ce . Sr P O :Dy ,Ce has its (CIE) chromaticity coordinates in the bluish-white-light region, near the standard illuminant D . The CIE 1913 chromaticity coordinates of Sr P O :Dy phosphors fall in the white-light region, and are adjacent to the ideal white-light coordinates. In addition, the colour temperature and colour tone of Sr P O :Dy could be adjusted by changing the relative concentration of Dy . In short, Sr P O :Dy can be a promising single-phased white-light emitting phosphor for near-UV (NUV) w-LEDs.