A dye-sensitized solar cell (DSC) using two dyes achieved high external quantum efficiency as sensitizers. We confirmed that terpyridine complex (black dye, Solaronix) and an indoline dye (D131, Mitsubishi Paper Mill) were adsorbed by the TiO2 electrode without either dye interfering with the electron transfer of the other dye to the electrode. The high performance of the new arrangement is made possible by the dissociation function of these two particular dyes. The multiple dye system achieved a power conversion efficiency of 11.0%. Moreover, the fabrication of the multiple dye system only mixed the two reagents in one pot.

No abstract

No abstract

No abstract

Plastic deformation study of Bi 2 Te 3 -related materials was performed. The ingots were grown by the Bridgman method using source materials with nominal compositions of Bi 0:5 Sb 1:5 Te 3 , Bi 2 Sb 2:85 Se 0:15 and Bi 1:8 Sb 0:2 Te 2:85 Se 0:15 . Disks were cut from the ingots, and were then deformed by either cold-pressing or by hot-pressing under pulse current heating. The crystal structures of the deformed samples were identified by X-ray diffraction. All diffraction peaks were assigned to the Bi 2 Te 3 structure, and the diffraction patterns indicate that the surfaces and bottoms of the samples were highly oriented in the hexagonal (00-l) plane. Hall effect measurements show the carrier concentration of the samples to be at an order of magnitude of 10 25 m À3 at room temperature. The power factor for the samples after hot-press deformation exceeded that for the original ingots. The results suggest that hot-press deformation enhances the thermoelectric properties of Bi 2 Te 3 -related materials.

The 2-stage functionally graded materials (FGM) of carrier concentration controlled PbTe were prepared by plasma activated sintering (PAS) using the discs cut from melt-grown PbTe ingots. The component materials of PbTe ingots were prepared by the Bridgman method with 2000 or 4000 molppm Pb12 as a n-type dopant. The thermoelectric characterization of the FGM was made in the temperature range from 300 to 700 K. The thermoelectric power ( a ) and the electrical conductivity ( a ) for the FGM was almost intermediate between those for the components. In the measured temperature range, the power factor ( @' a ) value for the FGM was found to exceed that for the components. This results indicate the possibility to realize high efficiency of energy conversion with the well designed FGM structure.

No abstract

No abstract