| Autor: |
Dhale, Shruti Prabhakar, Ugemuge, N. S., Singh, Vartika, Moharil, S. V. |
| Předmět: |
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| Zdroj: |
Journal of Materials Science; Sep2024, Vol. 59 Issue 34, p16158-16169, 12p |
| Abstrakt: |
New results on luminescence of Na2MgAlF7 activated with Ce3+ and/or Gd3+ are presented. Powder XRD confirms orthorhombic structure with Imm2 space group. Intense ultraviolet (UV) emission is observed for both the phosphors. Excitation for Gd3+ is in the form of narrow lines while a broad band marks the excitation spectrum for Ce3+. This broad band covers the most intense excitation line for Gd3+. By virtue of the close proximity of Ce3+and Gd3+ absorption, the former can act as a sensitizer for the latter. The excitation spectrum for Ce3+ also overlaps the emission from 275 nm UV chip. This was exploited for constructing phosphor converted UVB LED. Using Na2MgAlF7:Ce3+ phosphor and 275 nm UV chip, LED emitting broad band UVB light is demonstrated. Coating 275 nm chip with Na2MgAlF7:Ce3+, Gd3+phosphor, resulted in a LED with dominant emission at 311 nm. The results presented are important for obtaining UVB LEDs at lower prices. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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