The Role of OTS Density on Pentacene and C60 Nucleation,Thin Film Growth,and Transistor Performance |
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| Authors: | Ajay Virkar Stefan Mannsfeld Joon Hak Oh Michael F Toney Yih Horng Tan Gang‐yu Liu J Campbell Scott Robert Miller Zhenan Bao |
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| Affiliation: | 1. Department of Chemical Engineering, Stanford University 381 North South Mall, Stanford, CA 94305 (USA);2. Stanford Synchrotron Radiation Lab 2575 Sand Hill Road Menlo Park, CA 94025 (USA);3. Department of Chemistry, University of California One Shields Avenue, Davis, CA 95616 (USA);4. IBM Almaden Research Center San Jose, CA 95120 (USA) |
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| Abstract: | In organic thin film transistors (OTFTs), charge transport occurs in the first few monolayers of the semiconductor near the semiconductor/dielectric interface. Previous work has investigated the roles of dielectric surface energy, roughness, and chemical functionality on performance. However, large discrepancies in performance, even with apparently identical surface treatments, indicate that additional surface parameters must be identified and controlled in order to optimize OTFTs. Here, a crystalline, dense octadecylsilane (OTS) surface modification layer is found that promotes two‐dimensional semiconductor growth. Higher mobility is consistently achieved for films deposited on crystalline OTS compared to on disordered OTS, with mobilities as high as 5.3 and 2.3 cm2 V?1 s?1 for C60 and pentacene, respectively. This is a significant step toward morphological control of organic semiconductors which is directly linked to their thin film charge carrier transport. |
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| Keywords: | electronic structures flexible electronics self‐assembled monolayers semiconducting oligomers transistors |
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