Nanostructured columnar heterostructures of TiO2 and Cu 2O enabled by a thin-film self-assembly approach: Potential for photovoltaics


Polat Ö., Aytug T., Lupini A. R., Paranthaman P. M., ERTUĞRUL M., Bogorin D. F., ...More

Materials Research Bulletin, vol.48, no.2, pp.352-356, 2013 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 48 Issue: 2
  • Publication Date: 2013
  • Doi Number: 10.1016/j.materresbull.2012.10.044
  • Journal Name: Materials Research Bulletin
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.352-356
  • Keywords: A. Nanostructures, A. Thin films, B. Epitaxial growth, B. Sputtering, D. Microstructure
  • Istanbul Kültür University Affiliated: No

Abstract

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 n-type TiO2 and p-type 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 p-n 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.