1. Efficient energy transfer from Bi3+ to Mn2+ in CaZnOS for WLED application
- Author
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Jia-Yong Yuan, Dongyun Wan, Yu-Ting Fan, Zhi-Jun Zhang, Qianli Li, Yun-Ling Yang, and Jing-Tai Zhao
- Subjects
Materials science ,Analytical chemistry ,Phosphor ,02 engineering and technology ,Crystal structure ,Activation energy ,Color temperature ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Emission intensity ,0104 chemical sciences ,law.invention ,Ion ,Inorganic Chemistry ,law ,Chromaticity ,0210 nano-technology ,Light-emitting diode - Abstract
A series of Bi3+ and Mn2+ co-doped CaZnOS phosphors with a tunable emission color have been synthesized by a high temperature solid-state reaction method. Their crystal structure, spectroscopic properties, energy transfer and thermal quenching have been investigated systematically. An intense blue-green emission band at 485 nm and a red emission band at 616 nm were observed at an excitation wavelength of 375 nm, owing to the 3P1,0 → 1S0 transition of Bi3+ and the 4T1(4G) → 6A1(6S) transition of Mn2+, respectively. The tunable color from blue-green, white light to red light can be obtained by varying the Mn2+ ion concentration from 0.005 to 0.015 in CaZnOS:Bi3+. The decay time decreased from 642 to 273 ns with the Mn2+ ion concentration x increasing from 0.005 to 0.015, and the energy transfer efficiency ηT can reach up to 65% in the CaZnOS:Bi3+,0.015Mn2+ phosphor. As the temperature increases from 300 to 420 K, the emission intensity is maintained at 67%, and the activation energy Ea is estimated to be 0.28 eV. An LED fabricated using CaZnOS:Bi3+,0.01Mn2+ exhibited the chromaticity coordinates and corrected color temperature (CCT) of (0.338, 0.364) and 4655 K, respectively. These results validate the promising applications of the CaZnOS:Bi3+,Mn2+ phosphor in UV white LEDs.
- Published
- 2021
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