Liudmila L. Larina

New Oxide-Ion Conductors Ln2+xTi2-xO7-x/2 (Ln = Dy – Lu; x=0.096)

New oxide-ion conductors Ln2+xTi2-xO7-x/2 (Ln = Dy-Lu, x = 0.096; 35.5 mol. % Ln2O3· 64.5 mol.% TiO2)-LANTIOX with a disordered pyrochlore structure are obtained by coprecipitation with next thermal annealing at 1600°C. Their ionic conductivity in air at 740°C attains 5·10-3 S/cm for Ln2.096Ti1.904O6.952 (Ln= Lu, Yb), 10-3 S/cm for Ln2,096Ti1,904O6,952 (Ln=Tm, Er, Ho) and 10- 4S/cm for Dy2,096Ti1,904O6,952 due to the presence of defects in both the cation and anion sublattices. The materials contain ~4.8-10.6% LnTi anti-site defects. Ln2.096Ti1.904O6.952 ceramics are shown to be stable in the temperature range of 1400 to 1700°C. 1400°C-samples Ln2+xTi2-xO7-x/2 have lower ionic conductivity then 1600°C and 1690°C samples.

Effects of Bulk Photoconductivity on Photocurrent Action Spectra of Molecular p-n Heterojunction Solar Cells

bInstitute of Biochemical Physics RAS, 119991 Moscow, Russia We have investigated how bulk photoconductivity influences the photovoltaic parameters of zincphthalocyanine-fullerene ZnPc/C60 p-n heterojunction solar cells. The results indicate that the photocurrent action spectrum of a cell depends strongly on the photoconductivity and spectral characteristics of each component material. We therefore propose a model that simulates the action spectra of the short-circuit photocurrent in the molecular organic solar cells, and our model is based on the assumption that

Growth of an In x (OOH,S) y Buffer Layer and Its Application to Cu(In,Ga)(Se,S) 2 Solar Cells

As an alternative to a CdS buffer layer for Cu(In,Ga)Se2-based solar cells, we prepared In-based buffer layers using a chemical bath deposition method. XPS and XRD analyses revealed that the In-based buffer layers contained In2S3 and InOOH phases. Compared with CdS film, the In-based film, Inx(OOH,S)y, had higher optical transmittance and a shorter absorption edge. The Cu(In,Ga)(Se,S)2 solar cell with the Inx(OOH,S)y buffer layer had better photovoltaic properties than that with a conventional CdS buffer layer. The conversion efficiency of the best Cu(In,Ga)(Se,S)2 solar cell with Inx(OOH,S)y buffer layer was 12.55 % for an active area of 0.19 cm2.

Alternative molecular semiconductors for sensitizing nanocrystalline solar cells

The nanocrystalline TiO/sub 2/ based solar cells sensitized with different metal-phthalocyanines (MePc) have been fabricated and investigated. The energy conversion efficiency of TiO/sub 2//MePc system several times exceeds the one obtained for a solid state cell based on the same type of materials. The optical absorption spectra of sensitized nanocrystalline layers were studied. It was shown that condensed dye molecule clusters agglomerated in the vicinity of the TiO/sub 2/ surface do not contribute to the energy conversion process. We have also investigated the phthalocyanine-fullerene composites promising for the improvement of the conversion efficiency of MePc-sensitized solid-stated and nanocrystalline photovoltaic cells.

Paramagnetic structural defects and conductivity in hydrogenated nanocrystalline carbon-doped silicon films

The behavior of paramagnetic defects and dark conductivity in heterogeneous samples of hydrogenated nanocrystalline carbon-containing silicon (nc-SiC:H) prepared by the photo-CVD method is studied. It is shown that, with increasing carbon content in nc-SiC:H, a phase transition from a nanocrystalline to an amorphous structure occurs, producing a reduction in paramagnetic defect density and a significant decrease in the dark conductivity.

Novel Types of Dye-Sensitized and Perovskite-Based Tandem Solar Cells with a Common Counter Electrode

Novel types of tandem solar cells (TSC) based on dye-sensitized (DSC) and perovskite (PSC) solar cells including DSC/DSC and DSC/PSC configurations with a common counter electrode were fabricated and investigated. The measurements of PV parameters for tandem solar cells under AM1.5 light intensity conditions have shown that the highest power conversion efficiency (PCE) of 14.5% was obtained for the DSC/DSC tandem configuration. At the same time, investigations of DSC/PSC tandem solar cells demonstrated the prospective benefits of this tandem system for obtaining high PCE values.