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Dye-sensitized solar cells (DSSCs) based on titanium dioxide () have been extensively studied because of their promising low-cost alternatives to conventional semiconductor based solar cells. DSSCs consist of molecular dye at the interface between a liquid electrolyte and a mesoporous wide-bandgap semiconductor oxide. Most efforts for high conversion efficiencies have focused on dye and liquid electrolytes. However, interface engineering between dye and electrode is also important to reduce recombination and improve efficiency. In this work, for interface engineering, we deposited semiconducting ferroelectric with bandgap of 2.8 eV on nanoparticles and nanotubes. Photovoltaic properties of DSSCs were characterized as a function of thickness of . We showed that ferroelectric -coated electrodes enable to increase overall efficiency of DSSCs, which was associated with efficient electron transport due to internal electric field originating from electric polarization. It was suggested that engineering the dye- interface using ferroelectric materials as inorganic modifiers can be key parameter for enhanced photovoltaic performance of the cell.

By approaching the counter electrode to the carbon nanotubes (CNT) emitter, remarkable reduction of the cathode operating voltage has been accomplished in the under-gate CNT cathode structure. The peak emission current density of 2.5 mA/cm/sup 2/, which is sufficient for high brightness CNT field emission display, was obtained at the cathode-to-gate voltage of 57 V when the CNT-to-counter electrode gap was 2.2 /spl mu/m. The gate current was less than 10% of the anode current. The CNT cathode with low driving voltage can help the cost-effective field emission display implemented.

Describes a fast block-matching algorithm (BMA) for motion estimation exploiting the center-biased motion vector distribution characteristic more efficiently than the center-biased hybrid search (CBHS) algorithm does. This proposed algorithm, which is called the "fast center-biased hybrid search" (FCBHS), employs a hybrid method of a compact plus-shaped search, an X-shaped search and a diamond search to reduce the search point for motion vectors which are distributed within a 2-pixel radius of the center of the search window. Experimental results show that the FCBHS algorithm is about 44 times faster than a full search and 7-10% faster than the CBHS algorithm. Such a fast sub-optimal motion estimation algorithm is essential for situations which have limited processing power and constraints on the amount of power consumption, like real-time mobile video coding applications. This paper compares the popular sub-optimal block-matching technique with FCBHS, for which both the processing speed and the accuracy of motion compensation are tested over widely-used H.263 test video sequences.

An under-gate CNT cathode structure was fabricated and characterized. The purpose of this work is to fabricate a cathode with micron-sized CNT-to-counter electrode gap, d/sub G/. Scanning electron microscopy was used to characterize the fabricated cathode. Electrical measurements were made in a vacuum chamber. It was found that cathode-to-gate voltage decreases with decreasing d/sub G/. It was also observed that emitting layer made of high purity CNT powder offers higher performance in terms of emission site density.