The luminescence properties of Sr2–1.5x−1.5yP2O7:xDy3+,yCe3+ 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
• Subjects: Ammonium; Ammonium compounds; Cerium; Chemical precipitation; Chemical synthesis; Chromaticity; Colour; concentration quenching; Coprecipitation; Emission; Emissions; Energy transfer; Light; Light emitting diodes; Luminescence; Methods; nanoparticles; Optical properties; Phosphates; Phosphors; Photoluminescence; Photons; Precipitation; Properties; Quantum efficiency; Roasting; single phase; Sr2–1.5x−1.5yP2O7:xDy3+,yCe3; Ultraviolet radiation; White light
• ISSN: 1522-7235; 1522-7243
• DOI: 10.1002/bio.3363

A series of Sr2P2O7:Dy3+, Sr2P2O7:Ce3+ and Sr2P2O7:Dy3+,Ce3+ 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 Dy3+ concentration increasing in Sr2P2O7:Dy3+ phosphors, the luminescence intensity first increases, reaches maximum, and then decreases. A similar trend was followed by Sr2P2O7:Ce3+ with Ce3+concentration increasing. A successful attempt was made to initiate the energy transfer mechanism from Ce3+ to Dy3+ in the host lattice and an overlap between the emission band of Ce3+ and the excitation band of Dy3+ indicated that the Ce3+ → Dy3+ energy transfer may indeed exist. It is clear that the photoluminescence intensity of Dy3+ as well as the quantum efficiency of the phosphor can be enhanced markedly by co‐doping Ce3+. Sr2P2O7:Dy3+,Ce3+ has its (CIE) chromaticity coordinates in the bluish‐white‐light region, near the standard illuminant D65. The CIE 1913 chromaticity coordinates of Sr2P2O7:Dy3+ 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 Sr2P2O7:Dy3+ could be adjusted by changing the relative concentration of Dy3+. In short, Sr2P2O7:Dy3+ can be a promising single‐phased white‐light emitting phosphor for near‐UV (NUV) w‐LEDs.