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<p>To advance white light-emitting diodes (w-LEDs) technology, it is necessary to identify red-emitting phosphors possessing adequate luminescence characteristics as well as favorable resistance to heat and humidity. A series of Ag<sub>2</sub>GdNb<sub>5</sub>O<sub>15</sub>:<i>x</i>Sm<sup>3+</sup> (0.01 ≤ <i>x</i> ≤ 0.30&#xa0;mol) red phosphors are produced using a classical high-temperature solid-state synthesis. Phase purity is assessed by X-ray diffraction (XRD), which verified a single tetragonal lattice belonging to the<i> P</i>4/<i>mbm</i> space group. When excited at 481&#xa0;nm, the obtained phosphors show red emission peaked at 600&#xa0;nm, which arises from the electric dipole transition <sup>4</sup>G<sub>5/2</sub> → <sup>6</sup>H<sub>7/2</sub> of Sm<sup>3+</sup>. The best photoluminescence performance is achieved at a Sm<sup>3+</sup> content of 0.10&#xa0;mol. The phosphors show strong performance, with a high internal quantum efficiency (IQE) of 40.1%, color purity above 97.8%, and robust thermal stability. At 420&#xa0;K, the emission intensity is maintained at 88.0% of the room-temperature value, and after five heating–cooling cycles, it remained at 98.7% of the starting intensity. Moreover, outstanding humidity tolerance is also observed. Soaking the phosphor in deionized water for 48&#xa0;h lead to 70.3% retention of the initial emission. A white LED is subsequently assembled by placing the optimized phosphor together with YAG:Ce<sup>3+</sup> phosphor onto a 480&#xa0;nm blue chip. This device gives CIE chromaticity coordinates of (0.328, 0.307), a general color rendering index (<i>R</i><sub>a</sub>) of 84, and a correlated color temperature of 4758&#xa0;K. Collectively, these outcomes suggest that Ag<sub>2</sub>GdNb<sub>5</sub>O<sub>15</sub>:Sm<sup>3+</sup> constitutes a promising red phosphor with adequate thermal and moisture stability for potential w-LEDs application.</p>

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High thermal and moisture resistant Sm3+-doped Ag2GdNb5O15 blue-light-excited phosphor toward white LEDs

  • 期刊论文

  • 发表日期：

    2026年8月5日

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  • Minggen Tang,
  • Xinyi Zhang,
  • Kexin Zhang,
  • Minyue Wan,
  • Liran Cui,
  • Ya Yang,
  • Mubiao Xie,
  • Ruijin Yu

摘要

To advance white light-emitting diodes (w-LEDs) technology, it is necessary to identify red-emitting phosphors possessing adequate luminescence characteristics as well as favorable resistance to heat and humidity. A series of Ag2GdNb5O15:xSm3+ (0.01 ≤ x ≤ 0.30 mol) red phosphors are produced using a classical high-temperature solid-state synthesis. Phase purity is assessed by X-ray diffraction (XRD), which verified a single tetragonal lattice belonging to the P4/mbm space group. When excited at 481 nm, the obtained phosphors show red emission peaked at 600 nm, which arises from the electric dipole transition 4G5/2 → 6H7/2 of Sm3+. The best photoluminescence performance is achieved at a Sm3+ content of 0.10 mol. The phosphors show strong performance, with a high internal quantum efficiency (IQE) of 40.1%, color purity above 97.8%, and robust thermal stability. At 420 K, the emission intensity is maintained at 88.0% of the room-temperature value, and after five heating–cooling cycles, it remained at 98.7% of the starting intensity. Moreover, outstanding humidity tolerance is also observed. Soaking the phosphor in deionized water for 48 h lead to 70.3% retention of the initial emission. A white LED is subsequently assembled by placing the optimized phosphor together with YAG:Ce3+ phosphor onto a 480 nm blue chip. This device gives CIE chromaticity coordinates of (0.328, 0.307), a general color rendering index (Ra) of 84, and a correlated color temperature of 4758 K. Collectively, these outcomes suggest that Ag2GdNb5O15:Sm3+ constitutes a promising red phosphor with adequate thermal and moisture stability for potential w-LEDs application.