Study on Correlation between Structural and Electronic Properties of Fluorinated Oligothiophenes Transistors by Controlling Film Thickness
α,ω-diperfluorohexylquaterthiophene (DFH-4T) has been an attractive n-type material employed in the development of high-mobility organic field-effect transistors. This paper presents a systematic study of the relationship between DFH-4T transistor performance and film structure p...
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MDPI AG
2019-03-01
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| Online Access: | http://www.mdpi.com/2073-4352/9/3/144 |
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| author | Jui-Fen Chang Hua-Shiuan Shie Yaw-Wen Yang Chia-Hsin Wang |
| author_facet | Jui-Fen Chang Hua-Shiuan Shie Yaw-Wen Yang Chia-Hsin Wang |
| author_sort | Jui-Fen Chang |
| collection | DOAJ |
| description | α,ω-diperfluorohexylquaterthiophene (DFH-4T) has been an attractive n-type material employed in the development of high-mobility organic field-effect transistors. This paper presents a systematic study of the relationship between DFH-4T transistor performance and film structure properties as controlled by deposited thickness. When the DFH-4T thickness increases from 8 nm to 80 nm, the room-temperature field-effect mobility increases monotonically from 0.01 to 1 cm2·V−1·s−1, while the threshold voltage shows a different trend of first decrease then increase. The morphology of thin films revealed by atomic force microscopy shows a dramatic change from multilayered terrace to stacked rod like structures as the film thickness is increased. Yet the crystallite structure and the orientation of molecular constituent, as determined by X-ray diffraction and near-edge X-ray absorption fine structure respectively, do not differ much with respect to film thickness increase. Further analyses of low-temperature transport measurements with mobility-edge model demonstrate that the electronic states of DFH-4T transistors are mainly determined by the film continuity and crystallinity of the bottom multilayered terrace. Moreover, the capacitance-voltage measurements of DFH-4T metal-insulator-semiconductor diodes demonstrate a morphological dependence of charge injection from top contacts, which well explains the variation of threshold voltage with thickness. The overall study provides a deeper understanding of microstructural and molecular growth of DFH-4T film and clarify the structural effects on charge transport and injection for implementation of high-mobility top-contact transistors. |
| first_indexed | 2024-04-11T12:41:05Z |
| format | Article |
| id | doaj.art-91422d66e5944ac8ab1397a179eb4854 |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-04-11T12:41:05Z |
| publishDate | 2019-03-01 |
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| record_format | Article |
| series | Crystals |
| spelling | doaj.art-91422d66e5944ac8ab1397a179eb48542022-12-22T04:23:30ZengMDPI AGCrystals2073-43522019-03-019314410.3390/cryst9030144cryst9030144Study on Correlation between Structural and Electronic Properties of Fluorinated Oligothiophenes Transistors by Controlling Film ThicknessJui-Fen Chang0Hua-Shiuan Shie1Yaw-Wen Yang2Chia-Hsin Wang3Department of Optics and Photonics, National Central University, Zhongli 320, TaiwanDepartment of Optics and Photonics, National Central University, Zhongli 320, TaiwanNational Synchrotron Radiation Research Center, Hsinchu 300, TaiwanNational Synchrotron Radiation Research Center, Hsinchu 300, Taiwanα,ω-diperfluorohexylquaterthiophene (DFH-4T) has been an attractive n-type material employed in the development of high-mobility organic field-effect transistors. This paper presents a systematic study of the relationship between DFH-4T transistor performance and film structure properties as controlled by deposited thickness. When the DFH-4T thickness increases from 8 nm to 80 nm, the room-temperature field-effect mobility increases monotonically from 0.01 to 1 cm2·V−1·s−1, while the threshold voltage shows a different trend of first decrease then increase. The morphology of thin films revealed by atomic force microscopy shows a dramatic change from multilayered terrace to stacked rod like structures as the film thickness is increased. Yet the crystallite structure and the orientation of molecular constituent, as determined by X-ray diffraction and near-edge X-ray absorption fine structure respectively, do not differ much with respect to film thickness increase. Further analyses of low-temperature transport measurements with mobility-edge model demonstrate that the electronic states of DFH-4T transistors are mainly determined by the film continuity and crystallinity of the bottom multilayered terrace. Moreover, the capacitance-voltage measurements of DFH-4T metal-insulator-semiconductor diodes demonstrate a morphological dependence of charge injection from top contacts, which well explains the variation of threshold voltage with thickness. The overall study provides a deeper understanding of microstructural and molecular growth of DFH-4T film and clarify the structural effects on charge transport and injection for implementation of high-mobility top-contact transistors.http://www.mdpi.com/2073-4352/9/3/144organic film growthorganic transistorcharge transport and injection mechanisms |
| spellingShingle | Jui-Fen Chang Hua-Shiuan Shie Yaw-Wen Yang Chia-Hsin Wang Study on Correlation between Structural and Electronic Properties of Fluorinated Oligothiophenes Transistors by Controlling Film Thickness Crystals organic film growth organic transistor charge transport and injection mechanisms |
| title | Study on Correlation between Structural and Electronic Properties of Fluorinated Oligothiophenes Transistors by Controlling Film Thickness |
| title_full | Study on Correlation between Structural and Electronic Properties of Fluorinated Oligothiophenes Transistors by Controlling Film Thickness |
| title_fullStr | Study on Correlation between Structural and Electronic Properties of Fluorinated Oligothiophenes Transistors by Controlling Film Thickness |
| title_full_unstemmed | Study on Correlation between Structural and Electronic Properties of Fluorinated Oligothiophenes Transistors by Controlling Film Thickness |
| title_short | Study on Correlation between Structural and Electronic Properties of Fluorinated Oligothiophenes Transistors by Controlling Film Thickness |
| title_sort | study on correlation between structural and electronic properties of fluorinated oligothiophenes transistors by controlling film thickness |
| topic | organic film growth organic transistor charge transport and injection mechanisms |
| url | http://www.mdpi.com/2073-4352/9/3/144 |
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