Faculty of Engineering and Natural Sciences Seminar
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 advances in a vertically oriented two-component system that offers potential for future development of nanostructured thin film solar cells will be presented. Through a single-step deposition by magnetron sputtering, 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 will be demonstrated in the present talk. The composite films were structurally characterized to atomic resolution by a variety of analytical tools, and evaluated for preliminary optical properties using absorption measurements. Nearly atomically distinct TiO2–Cu2O interfaces (i.e., needed for possible active p–n junctions) were found. Moreover, an absorption profile that captures a wide range of the solar spectrum extending from ultraviolet to visible wavelengths was also exhibited. This high-quality materials system could lead to photovoltaic devices that can be optimized for both incident light absorption and carrier collection.