Transparent Oxide Substrates Research Articles

Laser machined ultrathin microscale platinum thermometers on transparent oxide substrates

Ultrathin microscale platinum resistive thermometers are of key value to transient temperature measurements. Neither transparent oxide substrates nor femtosecond laser patterning have been investigated for the fabrication of Pt thin film thermometers. Here, we have fabricated a laser machined, 50 μm wide and 50 nm thick, serpentine, Pt thin film sensor capable of sensing temperatures up to 650 °C over multiple heating and cooling cycles. Various materials and associated processing conditions were studied, including both sapphire and silica as transparent substrates, alumina and titanium dioxide as adhesion layers, and lastly alumina and silicon dioxide as capping layer. In-situ resistance monitoring helps verify the multi-cycle stability of the sensor and guide the optimization. 10 μm sized sensors could be laser-machined, but did not survive multiple heating and cooling cycles. We demonstrate that sensors with amorphous Ge thin layers can also repeatably measure temperatures up to 650 °C. It is anticipated that this sensor can be used for fast, high spatial resolution temperature probing for laser processing of thin films.

Effect of Surface Modifications on ZnO Nanorod Arrays Electrode for Dye-Sensitized Solar Cells

High quality, large area and well-oriented ZnO nanorod arrays electrodes were successfully synthesized on conductive transparent oxide substrates by low-temperature hydrothermal methods for dye-sensitized solar cells. Aiming at getting further enhancement and study the effect of the surface modification on cell performance, ZnO thin film and ZnO nanoparticles are carried out to modify the as-grown ZnO nanorod arrays. The morphology, structure and photoluminescence property of the modified ZnO electrodes are characterized in detail. Furthermore, the I-V characterization result shows that these modification methods have distinct influences on the performance of the cell based on ZnO nanorod arrays electrode. The overall conversion efficiency can be optimized by choosing the suitable modification route.

ZnO Nanowires Synthesized by Vapor Phase Transport Deposition on Transparent Oxide Substrates.

Zinc oxide nanowires have been synthesized without using metal catalyst seed layers on fluorine-doped tin oxide (FTO) substrates by a modified vapor phase transport deposition process using a double-tube reactor. The unique reactor configuration creates a Zn-rich vapor environment that facilitates formation and growth of zinc oxide nanoparticles and wires (20–80 nm in diameter, up to 6 μm in length, density <40 nm apart) at substrate temperatures down to 300°C. Electron microscopy and other characterization techniques show nanowires with distinct morphologies when grown under different conditions. The effect of reaction parameters including reaction time, temperature, and carrier gas flow rate on the size, morphology, crystalline structure, and density of ZnO nanowires has been investigated. The nanowires grown by this method have a diameter, length, and density appropriate for use in fabricating hybrid polymer/metal oxide nanostructure solar cells. For example, it is preferable to have nanowires no more than 40 nm apart to minimize exciton recombination in polymer solar cells.