Transparent Electrodes Based on Three-Dimensional Nanohelixes Light Harvesting Applications

We present transparent electrodes based on 3-dimensional nanohelix array for light harvesting applications. Arrays of nanohelixes fabricated by electron-beam oblique-angle deposition (OAD) of various metal oxides including TiO₂, WO₃ and ITO have been used for improving the performance of dye-sensitized solar cells (DSSCs), Photoelectrochemical (PEC) cells for water splitting, and organic photovoltaics (OPVs), respectively. Such light harvesting devices with transparent electrodes based on metal-oxides nanohelixes array show enhanced performances such as higher light absorption and power conversion efficiency than devices with conventional thin-film and sintered nanoparticle electrodes. This is attributed to the unique optical, microstructural, and electrical properties of metal-oxides nanohelixes such as enhanced light scattering and large specific area enabled by 3-dimensional geometry, and improved separation and transportation of photo-generated carriers by the near-single-crystallinity of metal-oxides nanohelixes. In addition, a number of applications including dichroic filters for high efficiency white light-emitting diodes, near-perfect anti-reflection coatings for solar cells, and high performance chemical sensors will be discussed.

References

[1] Hyunah Kwon and Jong Kyu Kim et al., Advanced Energy Materials, Accepted (2014).

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[3] Xing Yan et al., Advanced Functional Materials 23, 583 (2013).