2008 DEC 22 - (VerticalNews.com) -- According to a study from Russia, "Polymer solar cells have shown high potential to convert solar energy into electricity in a cost-effective way. One of the basic reasons limiting the polymer solar cell efficiency is insufficient absorption of the solar radiation by the active layer that limits the photocurrent."

  "To increase the photocurrent, one needs low-bandgap materials with strong absorption below 2 eV. In this work, we study two types of low-bandgap materials: ground-state charge-transfer complexes (CTCs) of a conjugated polymer, MEH-PPV (poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene]), and an exohedral metallocomplex of fullerene, (eta(2)-C-60)IrH(CO)[(+)DIOP] (IrC60). We demonstrate that the CTC formed between MEH-PPV and Conjugated molecules with high electron affinity, namely, 2,4,7-trinitrofluorenone (TNF) and 1,5-dinitroantraquinone (DNAQ), can have strong optical absorption extending down to the near infrared. We have observed that the photoexcited CTC can generate free charges. We also report on optical studies of IrC60 as a possible acceptor for polymer/fullerene solar cells. IrC60 strongly absorbs in the visible spectral range, in particular in the red part, and therefore has a potential for increasing the photocurrent as compared with polymer/methanofullerene solar cells," wrote S.A. Zapunidy and colleagues, Lomonosov Moscow State University ...read more

  2008 DEC 22 - (VerticalNews.com) -- "Thin films of microcrystalline hydrogenated silicon (mu c-Si:H) and nanocrystalline silicon carbide (nc-SiC:H) provide a new class of advanced nanostructured materials for solar photovoltaic (PV) devices. We have worked on the fabrication, characterization, and application of these materials for thin film PV solar cells based on amorphous silicon," scientists in South Korea report.

  "Here we present an overview of the preparation and characterization methods for heterogeneous SiC:H-based layers. Hydrogenated nc-SiC:H thin film materials with high crystalline volume fraction were deposited using photo-assisted chemical vapor deposition (photo-CVD) technique. The behavior of spin-containing dangling-bond (DB) defects was performed using electron spin resonance (ESR) and transport measurements as a function of sample crystallinity, doping level, and temperature," wrote K.S. Lim and colleagues ...read more

  2008 NOV 3 - (VerticalNews.com) -- "A method of synthesizing functional nanostructured powders by using reactive thermal plasma processing has been developed. Nanosized TiO2 powders have been synthesized by the plasma oxidation of solid and liquid precursors," scientists in Tsukuba, Japan report.

  "Quench gases, either injected from the shoulder of the reactor or injected counter to the plasma plume from the bottom of the reactor, are used to affect the quench rate and hence the particle size of the resultant powders. The experimental results are well supported by numerical analysis of the effects of the quench gas on flow pattern and temperature field of the thermal plasma as well as trajectory and temperature histories of the particles. The plasma-synthesized TiO2 nanoparticles showed phase preferences different from those synthesized by conventional wet processes. Nanosized particles of high crystallinity and nonequilibrium chemical composition were formed in one step by reactive thermal plasma processing. The plasma-synthesized nanoparticles were spherical and hardly agglomerated. Applications of highly functional nanoparticles are thought to require nanoparticles structured in the forms of (1) dispersoids, (2) fillers, and (3) patterns," wrote T. Ishigaki and colleagues ...read more