Nanodisk heterostructures consisting of monoclinic Cu(1.94)S and wurtzite CdS have been colloidally synthesized for the first time. Initially, hexagonal-shaped nanodisks of Cu(1.94)S were produced upon thermolysis of a copper complex in a solvent mixture of HDA and TOA at 250 °C. Rapid addition of Cd precursor to the reaction mixture resulted in the partial conversion of Cu(1.94)S into CdS, yielding Cu(1.94)S-CdS nanoheterostructures. The original morphology of the Cu(1.94)S nanodisks was conserved during the transformation. When Zn precursor was added together with the Cd precursor, Cu(1.94)S-Zn(x)Cd(1-x)S nanodisks were generated. These two-component nanostructures are potentially useful in the fabrication of heterojunction solar cells.

A study on low temperature processed solid state dye sensitized solar cell (LT-SDSC) is reported. The LT-SDSC uses a photoelectrode with a mesoporous TiO2 (mp-TiO2) film fabricated from a binder-free nanoparticle-TiO2 paste at room temperature, and a blocking layer of an amorphous TiO2 thin film deposited by atomic layer deposition (ALD) at 150 °C. A power conversion efficiency of 1.30% is obtained from the LT-SDSC with 0.9 μm mp-TiO2 layer and 20 nm ALD-TiO2 blocking layer, in cooperating with organic indoline dyes and a hole conductor, 2,2′,7,7′-Tetrakis-(N,N-di-4-methoxyphenylamino)-9,9′-spirobifluorene (Spiro-OMeTAD). The lower electron conductivity of the low-temperature-processed mp-TiO2 film and the amorphous blocking layer is equilibrated by using smaller thicknesses of the films. Ways to further boost the LT-SDSC performance are proposed. These LT-SDSC are potentially compatible with low cost plastic substrates and show promising manufacturing potential for low cost flexible SDSCs.

No abstract