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Carbon quantum dot-sensitized and tunable luminescence of Ca19Mg2(PO4)14:Ln3+ (Ln3+ = Eu3+ and/or Tb3+) nanocrystalline phosphors with abundant colors via a sol–gel process
- Source :
- Journal of Materials Chemistry C; 2/28/2019, Vol. 7 Issue 8, p2361-2375, 15p
- Publication Year :
- 2019
-
Abstract
- Herein, we demonstrate the characteristic blue luminescence of carbon quantum dots embedded in the Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript> nanocrystalline phosphor and carbon quantum dot-sensitized luminescence of Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript>:Ln<superscript>3+</superscript> (Ln<superscript>3+</superscript> = Eu<superscript>3+</superscript> and/or Tb<superscript>3+</superscript>) nanocrystalline phosphors with abundant colors. A series of Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript> and Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript>:Ln<superscript>3+</superscript> (Ln<superscript>3+</superscript> = Eu<superscript>3+</superscript> and/or Tb<superscript>3+</superscript>) nanocrystalline phosphors was prepared via a Pechini-type sol–gel process. With UV light excitation, the prepared Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript> nanocrystalline phosphors exhibited novel blue luminescence with a broad band from 374 to 600 nm peaking at 439 nm, which is ascribed to the embedded carbon quantum dots. Also, the obtained Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript>:Ln<superscript>3+</superscript> (Ln<superscript>3+</superscript> = Eu<superscript>3+</superscript> and/or Tb<superscript>3+</superscript>) nanocrystalline phosphors not only exhibited the characteristic broad band emission of the carbon quantum dots, but also the characteristic narrow line emission of the doped rare earth ions, i.e., the characteristic red emission of Eu<superscript>3+</superscript> (<superscript>5</superscript>D<subscript>J</subscript>→<superscript>7</superscript>F<subscript>J′</subscript> transitions, J, J′ = 0, 1, 2, 3) and the characteristic green emission of Tb<superscript>3+</superscript> (<superscript>5</superscript>D<subscript>4</subscript>→<superscript>7</superscript>F<subscript>J</subscript> transitions, J = 3, 4, 5, 6). Thus, energy transfer occurred from the carbon quantum dots to the doped Eu<superscript>3+</superscript> and/or Tb<superscript>3+</superscript> ions in the Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript>:Ln<superscript>3+</superscript> (Ln<superscript>3+</superscript> = Eu<superscript>3+</superscript> and/or Tb<superscript>3+</superscript>) nanocrystalline phosphors. The luminescence color of the Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript>:Ln<superscript>3+</superscript> (Ln<superscript>3+</superscript> = Eu<superscript>3+</superscript> and/or Tb<superscript>3+</superscript>) nanocrystalline phosphors could be tuned from blue to blue-green, green, white, pink, orange, red, etc. by changing the doping rare-earth ion concentration, species, and relative ratio of Eu<superscript>3+</superscript> to Tb<superscript>3+</superscript> ions. Furthermore, single-phase white-light luminescence was demonstrated in the Eu<superscript>3+</superscript>/Tb<superscript>3+</superscript> codoped Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript>:Ln<superscript>3+</superscript> nanocrystalline phosphors. Finally, the luminescence properties and mechanisms of the Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript> and Ca<subscript>19</subscript>Mg<subscript>2</subscript>(PO<subscript>4</subscript>)<subscript>14</subscript>:Ln<superscript>3+</superscript> (Ln<superscript>3+</superscript> = Eu<superscript>3+</superscript> and/or Tb<superscript>3+</superscript>) nanocrystalline phosphors were discussed. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20507526
- Volume :
- 7
- Issue :
- 8
- Database :
- Complementary Index
- Journal :
- Journal of Materials Chemistry C
- Publication Type :
- Academic Journal
- Accession number :
- 134862215
- Full Text :
- https://doi.org/10.1039/c8tc06599c