Critical Evaluation of Organic Thin-Film Transistor Models
The thin-film transistor (TFT) is a popular tool for determining the charge-carrier mobility in semiconductors, as the mobility (and other transistor parameters, such as the contact resistances) can be conveniently extracted from its measured current-voltage characteristics. However, the accuracy of...
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MDPI AG
2019-02-01
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| Series: | Crystals |
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| Online Access: | https://www.mdpi.com/2073-4352/9/2/85 |
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| author | Markus Krammer James W. Borchert Andreas Petritz Esther Karner-Petritz Gerburg Schider Barbara Stadlober Hagen Klauk Karin Zojer |
| author_facet | Markus Krammer James W. Borchert Andreas Petritz Esther Karner-Petritz Gerburg Schider Barbara Stadlober Hagen Klauk Karin Zojer |
| author_sort | Markus Krammer |
| collection | DOAJ |
| description | The thin-film transistor (TFT) is a popular tool for determining the charge-carrier mobility in semiconductors, as the mobility (and other transistor parameters, such as the contact resistances) can be conveniently extracted from its measured current-voltage characteristics. However, the accuracy of the extracted parameters is quite limited, because their values depend on the extraction technique and on the validity of the underlying transistor model. We propose here a new approach for validating to what extent a chosen transistor model is able to predict correctly the transistor operation. In the two-step fitting approach we have developed, we analyze the measured current-voltage characteristics of a series of TFTs with different channel lengths. In the first step, the transistor parameters are extracted from each individual transistor by fitting the output and transfer characteristics to the transistor model. In the second step, we check whether the channel-length dependence of the extracted parameters is consistent with the underlying model. We present results obtained from organic TFTs fabricated in two different laboratories using two different device architectures, three different organic semiconductors and five different materials combinations for the source and drain contacts. For each set of TFTs, our approach reveals that the state-of-the-art transistor models fail to reproduce correctly the channel-length-dependence of the transistor parameters. Our approach suggests that conventional transistor models require improvements in terms of the charge-carrier-density dependence of the mobility and/or in terms of the consideration of uncompensated charges in the carrier-accumulation channel. |
| first_indexed | 2024-04-11T18:05:29Z |
| format | Article |
| id | doaj.art-9cf684fb40d442aebd79a33804b0165f |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-04-11T18:05:29Z |
| publishDate | 2019-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-9cf684fb40d442aebd79a33804b0165f2022-12-22T04:10:20ZengMDPI AGCrystals2073-43522019-02-01928510.3390/cryst9020085cryst9020085Critical Evaluation of Organic Thin-Film Transistor ModelsMarkus Krammer0James W. Borchert1Andreas Petritz2Esther Karner-Petritz3Gerburg Schider4Barbara Stadlober5Hagen Klauk6Karin Zojer7Institute of Solid State Physics, NAWI Graz, Graz University of Technology, Petersgasse 16, 8010 Graz, AustriaMax Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, GermanyJoanneum Research Materials, Institute for Surface Technologies and Photonics, Franz-Pichler-Straße 30, 8160 Weiz, AustriaJoanneum Research Materials, Institute for Surface Technologies and Photonics, Franz-Pichler-Straße 30, 8160 Weiz, AustriaJoanneum Research Materials, Institute for Surface Technologies and Photonics, Franz-Pichler-Straße 30, 8160 Weiz, AustriaJoanneum Research Materials, Institute for Surface Technologies and Photonics, Franz-Pichler-Straße 30, 8160 Weiz, AustriaMax Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, GermanyInstitute of Solid State Physics, NAWI Graz, Graz University of Technology, Petersgasse 16, 8010 Graz, AustriaThe thin-film transistor (TFT) is a popular tool for determining the charge-carrier mobility in semiconductors, as the mobility (and other transistor parameters, such as the contact resistances) can be conveniently extracted from its measured current-voltage characteristics. However, the accuracy of the extracted parameters is quite limited, because their values depend on the extraction technique and on the validity of the underlying transistor model. We propose here a new approach for validating to what extent a chosen transistor model is able to predict correctly the transistor operation. In the two-step fitting approach we have developed, we analyze the measured current-voltage characteristics of a series of TFTs with different channel lengths. In the first step, the transistor parameters are extracted from each individual transistor by fitting the output and transfer characteristics to the transistor model. In the second step, we check whether the channel-length dependence of the extracted parameters is consistent with the underlying model. We present results obtained from organic TFTs fabricated in two different laboratories using two different device architectures, three different organic semiconductors and five different materials combinations for the source and drain contacts. For each set of TFTs, our approach reveals that the state-of-the-art transistor models fail to reproduce correctly the channel-length-dependence of the transistor parameters. Our approach suggests that conventional transistor models require improvements in terms of the charge-carrier-density dependence of the mobility and/or in terms of the consideration of uncompensated charges in the carrier-accumulation channel.https://www.mdpi.com/2073-4352/9/2/85organic thin-film transistortransistor model evaluationchannel-length dependencecontact resistancesmodeling contact effectsequivalent circuitcharge-carrier-mobility extraction |
| spellingShingle | Markus Krammer James W. Borchert Andreas Petritz Esther Karner-Petritz Gerburg Schider Barbara Stadlober Hagen Klauk Karin Zojer Critical Evaluation of Organic Thin-Film Transistor Models Crystals organic thin-film transistor transistor model evaluation channel-length dependence contact resistances modeling contact effects equivalent circuit charge-carrier-mobility extraction |
| title | Critical Evaluation of Organic Thin-Film Transistor Models |
| title_full | Critical Evaluation of Organic Thin-Film Transistor Models |
| title_fullStr | Critical Evaluation of Organic Thin-Film Transistor Models |
| title_full_unstemmed | Critical Evaluation of Organic Thin-Film Transistor Models |
| title_short | Critical Evaluation of Organic Thin-Film Transistor Models |
| title_sort | critical evaluation of organic thin film transistor models |
| topic | organic thin-film transistor transistor model evaluation channel-length dependence contact resistances modeling contact effects equivalent circuit charge-carrier-mobility extraction |
| url | https://www.mdpi.com/2073-4352/9/2/85 |
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