Finite Temperature Ultraviolet-Visible Dielectric Functions of Tantalum Pentoxide: A Combined Spectroscopic Ellipsometry and First-Principles Study
Tantalum pentoxide (Ta<sub>2</sub>O<sub>5</sub>) has demonstrated promising applications in gate dielectrics and microwave communication devices with its intrinsically high dielectric constant and low dielectric loss. Although there are numerous studies on the dielectric prop...
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MDPI AG
2022-06-01
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| Series: | Photonics |
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| author | Wenjie Zhang Zhaohui Zeng Tao Cheng Tianhao Fei Zhiwei Fu Xiaoyan Liu Jingyi Zhang Jia-Yue Yang |
| author_facet | Wenjie Zhang Zhaohui Zeng Tao Cheng Tianhao Fei Zhiwei Fu Xiaoyan Liu Jingyi Zhang Jia-Yue Yang |
| author_sort | Wenjie Zhang |
| collection | DOAJ |
| description | Tantalum pentoxide (Ta<sub>2</sub>O<sub>5</sub>) has demonstrated promising applications in gate dielectrics and microwave communication devices with its intrinsically high dielectric constant and low dielectric loss. Although there are numerous studies on the dielectric properties of Ta<sub>2</sub>O<sub>5</sub>, few studies have focused on the influence of external environmental changes (i.e., temperature and pressure) on the dielectric properties and the underlying physics is not fully understood. Herein, we synthesize Ta<sub>2</sub>O<sub>5</sub> thin films using the magnetron sputtering method, measure the ultraviolet-visible dielectric function at temperatures varying from 300 to 873 K by spectroscopic ellipsometry (SE), and investigate the temperature influence on the dielectric function from first principles. SE experiments observe that temperature has a nontrivial influence on the ultraviolet-visible dielectric function, accompanying the consistently decreased amplitude and increased broadening width for the dominant absorption peak. First-principles calculations confirm that the dominant absorption peak originates from the aggregated energy states near the valence band maximum (VBM) and conduction band minimum (CBM), and the theoretically predicted dielectric functions demonstrate good agreement with the SE experiments. Moreover, by performing first-principles molecular dynamics simulations, the finite-temperature dielectric function is predicted and its change trend with increasing temperature agrees overall with the SE measurements. This work explores the physical origins of temperature influence on the ultraviolet-visible dielectric function of Ta<sub>2</sub>O<sub>5</sub>, aimed at promoting its applications in the field of micro-/nanoelectronics. |
| first_indexed | 2024-03-09T06:03:05Z |
| format | Article |
| id | doaj.art-30fa432a2b584f5a900e771acd8f5157 |
| institution | Directory Open Access Journal |
| issn | 2304-6732 |
| language | English |
| last_indexed | 2024-03-09T06:03:05Z |
| publishDate | 2022-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Photonics |
| spelling | doaj.art-30fa432a2b584f5a900e771acd8f51572023-12-03T12:06:38ZengMDPI AGPhotonics2304-67322022-06-019744010.3390/photonics9070440Finite Temperature Ultraviolet-Visible Dielectric Functions of Tantalum Pentoxide: A Combined Spectroscopic Ellipsometry and First-Principles StudyWenjie Zhang0Zhaohui Zeng1Tao Cheng2Tianhao Fei3Zhiwei Fu4Xiaoyan Liu5Jingyi Zhang6Jia-Yue Yang7School of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaInstitute of Semiconductors, Guangdong Academy of Sciences, Guangzhou 510650, ChinaSchool of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaSchool of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaScience and Technology on Reliability Physics and Application of Electronic Component Laboratory, The 5th Electronics Research Institute of the Ministry of Industry and Information Technology, Guangzhou 511370, ChinaInstitute for Advanced Interdisciplinary Research (IAIR), University of Jinan, Jinan 250022, ChinaScience and Technology on Advanced Functional Composites Laboratory, Aerospace Research Institute of Materials and Processing Technology, Beijing 100076, ChinaSchool of Energy and Power Engineering, Shandong University, Jinan 250061, ChinaTantalum pentoxide (Ta<sub>2</sub>O<sub>5</sub>) has demonstrated promising applications in gate dielectrics and microwave communication devices with its intrinsically high dielectric constant and low dielectric loss. Although there are numerous studies on the dielectric properties of Ta<sub>2</sub>O<sub>5</sub>, few studies have focused on the influence of external environmental changes (i.e., temperature and pressure) on the dielectric properties and the underlying physics is not fully understood. Herein, we synthesize Ta<sub>2</sub>O<sub>5</sub> thin films using the magnetron sputtering method, measure the ultraviolet-visible dielectric function at temperatures varying from 300 to 873 K by spectroscopic ellipsometry (SE), and investigate the temperature influence on the dielectric function from first principles. SE experiments observe that temperature has a nontrivial influence on the ultraviolet-visible dielectric function, accompanying the consistently decreased amplitude and increased broadening width for the dominant absorption peak. First-principles calculations confirm that the dominant absorption peak originates from the aggregated energy states near the valence band maximum (VBM) and conduction band minimum (CBM), and the theoretically predicted dielectric functions demonstrate good agreement with the SE experiments. Moreover, by performing first-principles molecular dynamics simulations, the finite-temperature dielectric function is predicted and its change trend with increasing temperature agrees overall with the SE measurements. This work explores the physical origins of temperature influence on the ultraviolet-visible dielectric function of Ta<sub>2</sub>O<sub>5</sub>, aimed at promoting its applications in the field of micro-/nanoelectronics.https://www.mdpi.com/2304-6732/9/7/440dielectric functionspectroscopic ellipsometryfirst-principlestemperature dependence |
| spellingShingle | Wenjie Zhang Zhaohui Zeng Tao Cheng Tianhao Fei Zhiwei Fu Xiaoyan Liu Jingyi Zhang Jia-Yue Yang Finite Temperature Ultraviolet-Visible Dielectric Functions of Tantalum Pentoxide: A Combined Spectroscopic Ellipsometry and First-Principles Study Photonics dielectric function spectroscopic ellipsometry first-principles temperature dependence |
| title | Finite Temperature Ultraviolet-Visible Dielectric Functions of Tantalum Pentoxide: A Combined Spectroscopic Ellipsometry and First-Principles Study |
| title_full | Finite Temperature Ultraviolet-Visible Dielectric Functions of Tantalum Pentoxide: A Combined Spectroscopic Ellipsometry and First-Principles Study |
| title_fullStr | Finite Temperature Ultraviolet-Visible Dielectric Functions of Tantalum Pentoxide: A Combined Spectroscopic Ellipsometry and First-Principles Study |
| title_full_unstemmed | Finite Temperature Ultraviolet-Visible Dielectric Functions of Tantalum Pentoxide: A Combined Spectroscopic Ellipsometry and First-Principles Study |
| title_short | Finite Temperature Ultraviolet-Visible Dielectric Functions of Tantalum Pentoxide: A Combined Spectroscopic Ellipsometry and First-Principles Study |
| title_sort | finite temperature ultraviolet visible dielectric functions of tantalum pentoxide a combined spectroscopic ellipsometry and first principles study |
| topic | dielectric function spectroscopic ellipsometry first-principles temperature dependence |
| url | https://www.mdpi.com/2304-6732/9/7/440 |
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