High quantum yield of the Egyptian blue family of infrared phosphors (MCuSi4O10, M = Ca, Sr, Ba)
| Autor: | George C.-Y. Chan, Michael A. Zalich, Paul Berdahl, Simon K. Boocock, Sharon Chen, Ronnen Levinson |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Infrared Analytical chemistry General Physics and Astronomy Quantum yield Phosphor 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Fluorescence 0104 chemical sciences Impurity Yield (chemistry) 0210 nano-technology Absorption (electromagnetic radiation) Luminescence |
| Zdroj: | Journal of Applied Physics. 123:193103 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | The alkaline earth copper tetra-silicates, blue pigments, are interesting infrared phosphors. The Ca, Sr, and Ba variants fluoresce in the near-infrared (NIR) at 909, 914, and 948 nm, respectively, with spectral widths on the order of 120 nm. The highest quantum yield ϕ reported thus far is ca. 10%. We use temperature measurements in sunlight to determine this parameter. The yield depends on the pigment loading (mass per unit area) ω with values approaching 100% as ω → 0 for the Ca and Sr variants. Although maximum quantum yield occurs near ω = 0, maximum fluorescence occurs near ω = 70 g m−2, at which ϕ = 0.7. The better samples show fluorescence decay times in the range of 130 to 160 μs. The absorbing impurity CuO is often present. Good phosphor performance requires long fluorescence decay times and very low levels of parasitic absorption. The strong fluorescence enhances prospects for energy applications such as cooling of sunlit surfaces (to reduce air conditioning requirements) and luminescent solar concentrators. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|