Structural Colors on Al Surface via Capped Cu-Si<sub>3</sub>N<sub>4</sub> Bilayer Structure
Tunable structural colors have a multitude of applications in the beautification of mobile devices, in the decoration of artwork, and in the creation of color filters. In this paper, we describe a Metal-Insulator-Metal (MIM) design that can be used to systematically tune structural colors by alterin...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-02-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/14/2/471 |
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| author | M. A. Rahman Dongkyu Kim Deepshikha Arora Joo-Youl Huh Ji Young Byun |
| author_facet | M. A. Rahman Dongkyu Kim Deepshikha Arora Joo-Youl Huh Ji Young Byun |
| author_sort | M. A. Rahman |
| collection | DOAJ |
| description | Tunable structural colors have a multitude of applications in the beautification of mobile devices, in the decoration of artwork, and in the creation of color filters. In this paper, we describe a Metal-Insulator-Metal (MIM) design that can be used to systematically tune structural colors by altering the thickness of the top metal and intermediate insulator. Cu and Si<sub>3</sub>N<sub>4</sub> were selected as the top metal and intermediate insulator layers, respectively, and various reflection colors were printed on Al. To protect the Cu surface from scratchiness and oxidation, a number of capping layers, including SiO<sub>2</sub>, LPSQ, PMMA, and the commercially available clear coat ProtectaClear, were applied. In addition to their ability to protect Cu from a humid environment without deteriorating color quality, ProtectaClear and LPSQ coatings have minimal angle dependency. Furthermore, a bilayer of PMMA/SiO<sub>2</sub> can protect the Cu surface from the effects of humidity. In addition, the PMMA/SiO<sub>2</sub> and ProtectaClear/SiO<sub>2</sub> bilayers can also protect against corrosion on the Cu surface. The colors can be tuned by controlling the thickness of either the metal layer or intermediate insulator layer, and vivid structural colors including brown, dark orange, blue, violet, magenta, cyan, green-yellow, and yellow colors can be printed. The measured dielectric functions of Cu thin films do not provide any evidence of the plasmonic effect, and therefore, it is expected that the obtained colors are attributed to thin-film interference. |
| first_indexed | 2024-03-11T08:24:31Z |
| format | Article |
| id | doaj.art-b00234c37dd64b6d951bce885af652ed |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-11T08:24:31Z |
| publishDate | 2023-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-b00234c37dd64b6d951bce885af652ed2023-11-16T22:12:42ZengMDPI AGMicromachines2072-666X2023-02-0114247110.3390/mi14020471Structural Colors on Al Surface via Capped Cu-Si<sub>3</sub>N<sub>4</sub> Bilayer StructureM. A. Rahman0Dongkyu Kim1Deepshikha Arora2Joo-Youl Huh3Ji Young Byun4Extreme Materials Research Center, Korea Institute of Science & Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of KoreaExtreme Materials Research Center, Korea Institute of Science & Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of KoreaEngineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, SingaporeDepartment of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of KoreaExtreme Materials Research Center, Korea Institute of Science & Technology, 5, Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of KoreaTunable structural colors have a multitude of applications in the beautification of mobile devices, in the decoration of artwork, and in the creation of color filters. In this paper, we describe a Metal-Insulator-Metal (MIM) design that can be used to systematically tune structural colors by altering the thickness of the top metal and intermediate insulator. Cu and Si<sub>3</sub>N<sub>4</sub> were selected as the top metal and intermediate insulator layers, respectively, and various reflection colors were printed on Al. To protect the Cu surface from scratchiness and oxidation, a number of capping layers, including SiO<sub>2</sub>, LPSQ, PMMA, and the commercially available clear coat ProtectaClear, were applied. In addition to their ability to protect Cu from a humid environment without deteriorating color quality, ProtectaClear and LPSQ coatings have minimal angle dependency. Furthermore, a bilayer of PMMA/SiO<sub>2</sub> can protect the Cu surface from the effects of humidity. In addition, the PMMA/SiO<sub>2</sub> and ProtectaClear/SiO<sub>2</sub> bilayers can also protect against corrosion on the Cu surface. The colors can be tuned by controlling the thickness of either the metal layer or intermediate insulator layer, and vivid structural colors including brown, dark orange, blue, violet, magenta, cyan, green-yellow, and yellow colors can be printed. The measured dielectric functions of Cu thin films do not provide any evidence of the plasmonic effect, and therefore, it is expected that the obtained colors are attributed to thin-film interference.https://www.mdpi.com/2072-666X/14/2/471reflection colorsmetal-insulator-metal structureCu thin filmcapping layer |
| spellingShingle | M. A. Rahman Dongkyu Kim Deepshikha Arora Joo-Youl Huh Ji Young Byun Structural Colors on Al Surface via Capped Cu-Si<sub>3</sub>N<sub>4</sub> Bilayer Structure Micromachines reflection colors metal-insulator-metal structure Cu thin film capping layer |
| title | Structural Colors on Al Surface via Capped Cu-Si<sub>3</sub>N<sub>4</sub> Bilayer Structure |
| title_full | Structural Colors on Al Surface via Capped Cu-Si<sub>3</sub>N<sub>4</sub> Bilayer Structure |
| title_fullStr | Structural Colors on Al Surface via Capped Cu-Si<sub>3</sub>N<sub>4</sub> Bilayer Structure |
| title_full_unstemmed | Structural Colors on Al Surface via Capped Cu-Si<sub>3</sub>N<sub>4</sub> Bilayer Structure |
| title_short | Structural Colors on Al Surface via Capped Cu-Si<sub>3</sub>N<sub>4</sub> Bilayer Structure |
| title_sort | structural colors on al surface via capped cu si sub 3 sub n sub 4 sub bilayer structure |
| topic | reflection colors metal-insulator-metal structure Cu thin film capping layer |
| url | https://www.mdpi.com/2072-666X/14/2/471 |
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