Woo HJ, Hadrick K, Kim T. Thermally Induced Morphological and Structural Transformations on Eu
2+/Eu
3+-Coactivated Calcium Silicate Nanophosphors.
ACS APPLIED OPTICAL MATERIALS 2024;
2:445-452. [PMID:
38544700 PMCID:
PMC10964230 DOI:
10.1021/acsaom.3c00456]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/29/2024] [Accepted: 02/13/2024] [Indexed: 04/28/2024]
Abstract
This study presents an approach for synthesizing Eu2+/Eu3+-coactivated Ca2SiO4 nanophosphors, by adjusting the ratio of both activators within a singular host material. Utilizing a hydrothermal method complemented by a postreduction sintering process, we fabricated a series of phosphors characterized by uniform 30-50 nm spherical nanoparticles. These engineered phosphors manifest multichannel luminescence properties and exhibit simultaneous blue and red emission from Eu2+ and Eu3+, respectively. Meticulous control of the 5% H2-95% N2 reduction temperature allowed for precise tuning of the Eu2+ and Eu3+ ions within the host lattice, which enabled the strategic adjustment of their luminescent outputs. Utilizing X-ray photoelectron spectroscopy (XPS), we could discern subtle alterations in the europium oxidation state. By using a transmission electron microscope (TEM) and an X-ray diffractometer (XRD), we found that the subsequent changes by reductive sintering to particle size, morphology, and mixed crystal structures influenced the materials' luminescent characteristics. Our findings herald a significant advancement in solid-state lighting, with the potential for the use of Eu2+/Eu3+-coactivated calcium silicate nanophosphors to develop white light emission technologies endowed with enhanced color rendering and luminous efficacy.
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