Luminescence enhancement of Mn4+-activated double-perovskite phosphors for LEDs through a co-replacement strategy |
| |
Authors: | Qianwen Cao Liang Li Jing Xie Yuan Feng Wenming Wang Yan Pan Xiantao Wei Yong Li |
| |
Affiliation: | 1. School of Microelectronics & Data Science, Anhui University of Technology, Maanshan, China;2. Analysis and Testing central Facility, Anhui University of Technology, Maanshan, China;3. Physics Experiment Teaching Center, School of Physical Sciences, University of Science and Technology of China, Hefei, China |
| |
Abstract: | Phosphors doped with Mn4+ ions have strong emission in the red and far-red light regions and are therefore used as red phosphors for indoor plant cultivation light-emitting diodes (LEDs) and white LEDs (w-LEDs). This paper introduces La2Mg(Mg1/3Ta2/3)O6: Mn4+ (Mg2La3TaO9: Mn4+) red phosphors prepared by conventional high-temperature solid-phase method. The broad excitation band of Mg2La3TaO9: Mn4+ phosphor is effectively excited by ultraviolet and blue light in the range of 250–600 nm, with the emission of 707 nm centered on far-red light. The phosphor has a high color purity of 99.07% and an internal quantum efficiency of 59.87%. To further enhance the performance of the phosphor, a cation substitution method was adopted in this paper to synthesize La2Mg(Al1/2Ta1/2)O6: Mn4+ phosphor by replacing 1/3Mg2+–2/3Ta5+] in La2Mg(Mg1/3Ta2/3)O6: Mn4+ with 1/2Al3+–1/2Ta5+]. The luminescence intensity and thermal stability of the samples were enhanced. The emission spectrum of the Mg2La3TaO9: Mn4+ samples matched well with the phytochrome PFR (phytochrome that absorbs far-red light) and is suitable for the preparation of LEDs for indoor plant cultivation. The concentration quenching effect of the samples was investigated, the main mechanism of which is the electric dipole–dipole interaction. Red LEDs and w-LEDs devices were prepared with the synthesized phosphors that produce light stably at different currents. The w-LEDs have a correlated color temperature of 5310 K and a color rendering index of 80.1. Therefore, these samples are expected to be used as red components for w-LEDs. |
| |
Keywords: | cationic co-substitution light-emitting diodes Mn4+-activated phosphor octahedral distortion |
|
|