Improving charge injection in high-mobility rubrene crystals: From contact-limited to channel-dominated transistors
| Autor: | Tino Zimmerling, Bertram Batlogg |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 115:164511 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | With progressively improving charge carrier mobility in organic semiconductors and miniaturization of organic field-effect transistors (OFETs), low contact resistances become ever more important. To study the capabilities of metal electrodes in OFETs and to explore the transition from contact-limited to channel-dominated transistor operation, we used flip-crystal FETs with gold electrodes having different contact resistances Rc to high-quality rubrene crystals. 4-terminal transfer and output measurements reveal that Rc decreases from 105–106 Ω cm for 15 min air exposure to 3 × 103 Ωcm for at least 5 h air exposure of the gold electrodes before the flip-crystal FET is assembled. We conclude the reduction of Rc to be caused by a growing contamination layer on the gold electrodes that weakens the electrostatic coupling between rubrene crystal and gold electrode, and lowers the Schottky contact diode parameter V0. In channel-dominated (low Rc) FETs, the mobility is in the range of 10–17 cm2/(Vs); in contrast,... |
| Databáze: | OpenAIRE |
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