On the Quantum Confinement Effects in Ultrathin PdO Films by Experiment and Theory
Radio frequency magnetron sputtering conducted in a high vacuum with a base pressure of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>1</mn><mo>×</mo><msup><mn>10&...
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MDPI AG
2022-12-01
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| Online Access: | https://www.mdpi.com/1996-1944/15/23/8700 |
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| author | Alexandros Barnasas Christos S. Garoufalis Dimitrios I. Anyfantis Panagiotis Poulopoulos Sotirios Baskoutas |
| author_facet | Alexandros Barnasas Christos S. Garoufalis Dimitrios I. Anyfantis Panagiotis Poulopoulos Sotirios Baskoutas |
| author_sort | Alexandros Barnasas |
| collection | DOAJ |
| description | Radio frequency magnetron sputtering conducted in a high vacuum with a base pressure of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>1</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup></mrow></semantics></math></inline-formula> mbar was used to deposit ultrathin palladium films on Corning glass. The thickness of these films ranged from 0.4 to 13 nanometers. PdO films were produced after being post-annealed in a furnace at temperatures of 530 degrees Celsius in the presence of air. The results of an atomic force microscopy study showed that the material possessed a high crystalline quality with a low roughness. When looking at Tauc plots to determine the position of the direct optical band gap, the thicker films show a value that is relatively close to 2.2 eV. When the film thickness was reduced all the way down to 0.7 nm, a significant “blue shift” of more than 0.5 eV was observed. In order to provide a more in-depth understanding of the experiment, theoretical calculations based on the Hartree–Fock approximation as applied to an electron-hole system were performed in the framework of the effective mass approximation. The findings are regarded as empirical proof of the existence of quantum confinement effects. |
| first_indexed | 2024-03-09T17:41:56Z |
| format | Article |
| id | doaj.art-b5c43d857e1a450c979b1cbc227949bd |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T17:41:56Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-b5c43d857e1a450c979b1cbc227949bd2023-11-24T11:32:41ZengMDPI AGMaterials1996-19442022-12-011523870010.3390/ma15238700On the Quantum Confinement Effects in Ultrathin PdO Films by Experiment and TheoryAlexandros Barnasas0Christos S. Garoufalis1Dimitrios I. Anyfantis2Panagiotis Poulopoulos3Sotirios Baskoutas4Materials Science Department, University of Patras, 26504 Patras, GreeceMaterials Science Department, University of Patras, 26504 Patras, GreeceMaterials Science Department, University of Patras, 26504 Patras, GreeceMaterials Science Department, University of Patras, 26504 Patras, GreeceMaterials Science Department, University of Patras, 26504 Patras, GreeceRadio frequency magnetron sputtering conducted in a high vacuum with a base pressure of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>1</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup></mrow></semantics></math></inline-formula> mbar was used to deposit ultrathin palladium films on Corning glass. The thickness of these films ranged from 0.4 to 13 nanometers. PdO films were produced after being post-annealed in a furnace at temperatures of 530 degrees Celsius in the presence of air. The results of an atomic force microscopy study showed that the material possessed a high crystalline quality with a low roughness. When looking at Tauc plots to determine the position of the direct optical band gap, the thicker films show a value that is relatively close to 2.2 eV. When the film thickness was reduced all the way down to 0.7 nm, a significant “blue shift” of more than 0.5 eV was observed. In order to provide a more in-depth understanding of the experiment, theoretical calculations based on the Hartree–Fock approximation as applied to an electron-hole system were performed in the framework of the effective mass approximation. The findings are regarded as empirical proof of the existence of quantum confinement effects.https://www.mdpi.com/1996-1944/15/23/8700thin filmsPdOoptical propertiesquantum confinementpotential morphing method |
| spellingShingle | Alexandros Barnasas Christos S. Garoufalis Dimitrios I. Anyfantis Panagiotis Poulopoulos Sotirios Baskoutas On the Quantum Confinement Effects in Ultrathin PdO Films by Experiment and Theory Materials thin films PdO optical properties quantum confinement potential morphing method |
| title | On the Quantum Confinement Effects in Ultrathin PdO Films by Experiment and Theory |
| title_full | On the Quantum Confinement Effects in Ultrathin PdO Films by Experiment and Theory |
| title_fullStr | On the Quantum Confinement Effects in Ultrathin PdO Films by Experiment and Theory |
| title_full_unstemmed | On the Quantum Confinement Effects in Ultrathin PdO Films by Experiment and Theory |
| title_short | On the Quantum Confinement Effects in Ultrathin PdO Films by Experiment and Theory |
| title_sort | on the quantum confinement effects in ultrathin pdo films by experiment and theory |
| topic | thin films PdO optical properties quantum confinement potential morphing method |
| url | https://www.mdpi.com/1996-1944/15/23/8700 |
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