Directionally Solidified Cobalt-Doped MgO-MgAl<sub>2</sub>O<sub>4</sub> Eutectic Composites for Selective Emitters
Cobalt-doped MgO-MgAl<sub>2</sub>O<sub>4</sub> eutectic composites were explored for their use as selective emitters for thermophotovoltaic devices. Eutectic ceramic rods with different cobalt content were directionally solidified by using the laser floating zone technique at...
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MDPI AG
2022-10-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/20/10254 |
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| author | Rosa I. Merino Patricia B. Oliete Bibi Malmal Moshtaghioun Daniel Sola José I. Peña |
| author_facet | Rosa I. Merino Patricia B. Oliete Bibi Malmal Moshtaghioun Daniel Sola José I. Peña |
| author_sort | Rosa I. Merino |
| collection | DOAJ |
| description | Cobalt-doped MgO-MgAl<sub>2</sub>O<sub>4</sub> eutectic composites were explored for their use as selective emitters for thermophotovoltaic devices. Eutectic ceramic rods with different cobalt content were directionally solidified by using the laser floating zone technique at two processing rates to obtain microstructures with different domain sizes. Thermal emission between 1000 °C and 1500 °C and optical properties (reflectance and transmittance) at room temperature were measured in the Co-doped composites and the effect on microstructure and cobalt content was investigated. Thermal emission consisted of an intense broad band at about 1.67 µm matching with the bandgap of the InGaAs cell. The emission was ascribed to the de-excitation from the <sup>4</sup>T<sub>1</sub>(F) multiplet to the <sup>4</sup>A<sub>2</sub>(F) ground state of the thermally excited Co ions located in the tetrahedral sites of the MgAl<sub>2</sub>O<sub>4</sub> phase. The selectivity of the thermal emission showed a decrease with the cobalt content due to the enhancement of other electronic transitions, which leads to keeping the cobalt content in these composites at low levels (<0.15% at Co) for their use as selective emitters. |
| first_indexed | 2024-03-09T20:48:07Z |
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| id | doaj.art-ebccf5b125a641459ff556a8b364afa0 |
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| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-09T20:48:07Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
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| spelling | doaj.art-ebccf5b125a641459ff556a8b364afa02023-11-23T22:41:39ZengMDPI AGApplied Sciences2076-34172022-10-0112201025410.3390/app122010254Directionally Solidified Cobalt-Doped MgO-MgAl<sub>2</sub>O<sub>4</sub> Eutectic Composites for Selective EmittersRosa I. Merino0Patricia B. Oliete1Bibi Malmal Moshtaghioun2Daniel Sola3José I. Peña4Instituto de Nanociencia y Materiales de Aragón, Universidad de Zaragoza-CSIC, 50018 Zaragoza, SpainInstituto de Nanociencia y Materiales de Aragón, Universidad de Zaragoza-CSIC, 50018 Zaragoza, SpainInstituto de Nanociencia y Materiales de Aragón, Universidad de Zaragoza-CSIC, 50018 Zaragoza, SpainLaboratorio de Óptica, Centro de Investigación en Óptica y Nanofísica, Campus Espinardo, Universidad de Murcia, 30100 Murcia, SpainInstituto de Nanociencia y Materiales de Aragón, Universidad de Zaragoza-CSIC, 50018 Zaragoza, SpainCobalt-doped MgO-MgAl<sub>2</sub>O<sub>4</sub> eutectic composites were explored for their use as selective emitters for thermophotovoltaic devices. Eutectic ceramic rods with different cobalt content were directionally solidified by using the laser floating zone technique at two processing rates to obtain microstructures with different domain sizes. Thermal emission between 1000 °C and 1500 °C and optical properties (reflectance and transmittance) at room temperature were measured in the Co-doped composites and the effect on microstructure and cobalt content was investigated. Thermal emission consisted of an intense broad band at about 1.67 µm matching with the bandgap of the InGaAs cell. The emission was ascribed to the de-excitation from the <sup>4</sup>T<sub>1</sub>(F) multiplet to the <sup>4</sup>A<sub>2</sub>(F) ground state of the thermally excited Co ions located in the tetrahedral sites of the MgAl<sub>2</sub>O<sub>4</sub> phase. The selectivity of the thermal emission showed a decrease with the cobalt content due to the enhancement of other electronic transitions, which leads to keeping the cobalt content in these composites at low levels (<0.15% at Co) for their use as selective emitters.https://www.mdpi.com/2076-3417/12/20/10254MgO/MgAl<sub>2</sub>O<sub>4</sub>directionally solidified ceramic eutecticscobalt-doped selective emittersthermophotovoltaic |
| spellingShingle | Rosa I. Merino Patricia B. Oliete Bibi Malmal Moshtaghioun Daniel Sola José I. Peña Directionally Solidified Cobalt-Doped MgO-MgAl<sub>2</sub>O<sub>4</sub> Eutectic Composites for Selective Emitters Applied Sciences MgO/MgAl<sub>2</sub>O<sub>4</sub> directionally solidified ceramic eutectics cobalt-doped selective emitters thermophotovoltaic |
| title | Directionally Solidified Cobalt-Doped MgO-MgAl<sub>2</sub>O<sub>4</sub> Eutectic Composites for Selective Emitters |
| title_full | Directionally Solidified Cobalt-Doped MgO-MgAl<sub>2</sub>O<sub>4</sub> Eutectic Composites for Selective Emitters |
| title_fullStr | Directionally Solidified Cobalt-Doped MgO-MgAl<sub>2</sub>O<sub>4</sub> Eutectic Composites for Selective Emitters |
| title_full_unstemmed | Directionally Solidified Cobalt-Doped MgO-MgAl<sub>2</sub>O<sub>4</sub> Eutectic Composites for Selective Emitters |
| title_short | Directionally Solidified Cobalt-Doped MgO-MgAl<sub>2</sub>O<sub>4</sub> Eutectic Composites for Selective Emitters |
| title_sort | directionally solidified cobalt doped mgo mgal sub 2 sub o sub 4 sub eutectic composites for selective emitters |
| topic | MgO/MgAl<sub>2</sub>O<sub>4</sub> directionally solidified ceramic eutectics cobalt-doped selective emitters thermophotovoltaic |
| url | https://www.mdpi.com/2076-3417/12/20/10254 |
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