Intellectual Property Office

Non-Confidential Disclosures

“Vertically Aligned Single Crystal Nanowires on TCO Substrates”

PSU Inv. Disc. No 3482
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Keywords

Solar power, photocatalysis, photochromism, photovoltaics and gas sensors

Inventors:

Craig Grimes, Xinjian Feng

Links:

Inventor Website

Background:

Transparent conducting oxide (TCO) substrates play the key role for the fabrication of Si-based thin film and other thin film solar cells. TCO material is used to illuminate the device and to serve as one of the solar cell electrodes. The ideal TCO provides high transparency over a wide spectral range with high conductivity and high carrier mobility. Previously, there has been no synthetic method to grow aligned, densely packed single crystal nanowire arrays on TCO substrates.

Invention description:

The subject invention represents a straight-forward low temperature method to prepare single-crystal titanium oxide (TiO2) nanowire arrays up to 4 µm long on TCO glass under mild hydrothermal conditions. Field-emission scanning electron microscope images showed highly uniformed and densely packed array of nanowires, which were almost perpendicular from the substrate with widths ranging from 15-35 nm. High resolution transmission electron microscope confirmed that the nanowires are single crystalline. The electron mobility of the invention's material is 1cm2 V-1s-1, over two orders of magnitude larger than those for nanoparticulate TiO2 films. The photocurrent of the TiO2 nanowire array-based electrode increases sharply reaching saturation at -0.25 V indicative of both low series resistance and facile separation of the photogenerated charges. Results indicate that the nanowire arrays have high light absorption and low charge recombination.

Advantages:

• Using a 2.0 TiO2 µm nanowire array sample under AM 1.5 illumination, the overall photoconversion efficiency reached 6.25%. Researchers are working to increase this.
• Synthesis method is simple, low cost and highly reproducible.
• May be extended to the synthesis of other metal oxide semiconductors in single crystal nanowire array form.

Contact:

Matthew Smith
Sr. Technology Licensing Officer
Intellectual Property Office
113 Technology Center
The Pennsylvania State Univ.
University Park, PA 16802-7000
Phone: (814) 863-1212
Fax: (814) 865-3591
E-mail:mds126@psu.edu