Nanostructured columnar heterostructures of TiO₂ and Cu₂O enabled by a thin-film self-assembly approach: Potential for photovoltaics

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• 作者：&Ouml ; zg&uuml ; r Polat^a ; ^b ; ¹ ; ^{ozgurpolat7@gmail.com} ; Tolga Aytug^a ; ^{aytugt@ornl.gov} ; Andrew R. Lupini^a ; Parans M. Paranthaman^a ; Mehmet Ertugrul^c ; Daniela F. Bogorin^a ; Harry M. Meyer^a ; Wei Wang^a ; Stephen J. Pennycook^a ; David K. Christen^a
• 关键词：A. Nanostructures ; A. Thin films ; B. Sputtering ; B. Epitaxial growth ; D. Microstructure
• 刊名：Materials Research Bulletin
• 出版年：2013
• 出版时间：February, 2013
• 年：2013
• 卷：48
• 期：2
• 页码：352-356
• 全文大小：560 K

文摘

Significant efforts are being devoted to the development of multifunctional thin-film heterostructures and nanostructured material architectures for components with novel applications of superconductivity, multiferroicity, solar photocatalysis and energy conversion. In particular, nanostructured assemblies with well-defined geometrical shapes have emerged as possible high efficiency and economically viable alternatives to planar photovoltaic thin-film architectures. By exploiting phase-separated self-assembly, here we present advances in a vertically oriented two-component system that offers potential for future development of nanostructured thin film solar cells. Through a single-step deposition by magnetron sputtering, we demonstrate growth of an epitaxial, composite film matrix formed as self-assembled, well ordered, phase segregated, and oriented nanopillars of m>n-typem> TiO₂ and m>p-typem> Cu₂O. The composite films were structurally characterized to atomic resolution by a variety of analytical tools, and evaluated for preliminary optical properties using absorption measurements. We find nearly atomically distinct TiO₂-Cu₂O interfaces (i.e., needed for possible active m>p-nm> junctions), and an absorption profile that captures a wide range of the solar spectrum extending from ultraviolet to visible wavelengths. This high-quality materials system could lead to photovoltaic devices that can be optimized for both incident light absorption and carrier collection.