Lyotropic Self-Assembly of High-Aspect-Ratio Semiconductor Nanowires of Single-Crystal ZnO

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• 作者：Shanju Zhang ; Pawel W. Majewski ; Gayatri Keskar ; Lisa D. Pfefferle ; Chinedum O. Osuji
• 刊名：Langmuir
• 出版年：2011
• 出版时间：September 20, 2011
• 年：2011
• 卷：27
• 期：18
• 页码：11616-11621
• 全文大小：1049K
• 年卷期：v.27,no.18(September 20, 2011)
• ISSN：1520-5827

文摘

Lyotropic nanowire dispersions are attractive precursors for semiconductor device fabrication because they permit the alignment control of active nanomaterials. The reliable production of nanowire-based mesophases, however, is very challenging in practice. We show that appropriately functionalized high-aspect-ratio nanowires of single-crystal ZnO spontaneously form nematic phases in organic and aqueous media. These systems show isotropic, biphasic, and nematic phases on increasing concentration, in reasonable agreement with Onsager鈥檚 theory for rigid rods interacting via excluded volume. Suspensions were readily processed to produce films with large-area monodomains of aligned nanowires. Imprints of the director field in quiescently dried films display a propensity for bend deformation in the organic mesophase versus splay deformation in the aqueous case, suggesting that system elasticity may be tuned via surface functionalization. These results provide critical insight for the utilization of semiconductor nanowires as novel mesogens and further enable the use of solution-based routes for fabricating optoelectronic devices.