Nanocrystalline tin-oxide

The sensitive layers that have been used throughout this book consist of nanocrystalline tin-oxide thick films. The resistance change is the result of a multitude of reactions taking place at the surface and in the bulk. This resistance change depends also on the morphology of the sensitive layer and the contact-electrode geometry. Due... 

The on-chip hotplate temperature controller had a resolution of better than 2 °C. A high CO sensitivity was measured with a 0.2 wt % doped Pd nanocrystalline tin oxide, the resolution was 0.2 ppm CO, and the detection limit was 0.1 ppm CO. Such... 

Ferrere, S. Zaban, A. Gregg, B. A. Dye sensitization of nanocrystalline tin oxide by perylene derivative, J. Phys. Chem. 1997, B101, 4490. 

Feng and coworkers prepared nanocrystalline tin oxide on monolithic mesoporous silica starting from Sn(acac)2Cl2 by simple immersing of the substrate in the precursor solution. Heat treatment (300-600 °C) leads to nanocomposites with a large specific surface area. The electrical properties of these nanocomposites were also investigated. The authors found an inverse correlation between the precursor concentration and the electrical resistivities of the samples. ... 

Davis S. R., Chadwick A. V., and Wright 1. D., The effects of crystallite growth and dopant migration on the carhon monoxide sensing characteristics of nanocrystalline tin oxide based sensor materials, J. Mater. Chem., 8, 2065-2071, 1998. 

Nanophase Technology Corporation has developed a silver-doped nanocrystalline tin oxide aimed at antimicrobial and conductive apphcations. It consists of particles in the 30 nm size range with a silver content of 3%. The company expects to develop similar products. 

Fenere S, Zaban A, Gregg BA (1997) Dye sensitization of nanocrystalline tin oxide by ptayltme derivatives. J Phys Chem B 101(23) 4490-4493... 

The state of the art regenerative solar cell consists of the sensitizer cis-Ru(dcb)2(NCS)2 anchored to colloidal anatase Ti02 films with an Lil-l2 organic electrolyte. An i-V curve recorded with 1000 W m of air mass 1.5 illumination at 25 °C is shown in Figure 25 [154]. From these data, a Eqc of 0.79 V, an 4c of 4.83 mA, a fill factor of 0.71 and an of 0.11 were obtained. The active area of the electrode was kept low, 0.249 cm, to minimize resisitive losses associated with the tin oxide glass and the nanocrystalline semiconductor film. The power efficiency was not significantly changed when the temperature was raised from 20 to 60 °C. 

The resistance of the nanocomposite film was also greater than that of the pure tin oxide film, most likely because the presence of the CNTs had led to the introduction of pores. Nonetheless, this illustrates the potential of these nanocomposite-type materials - where both phases are nanocrystalline - in the field of gas sensors. 

The active layer of the DSSCs consists of a mesoporous nanocrystalline metal oxide (typically titanium dioxide or zinc oxide) deposited on fluorine-doped tin oxide (FTO) electrode and covered with some organic or organometaUic dye. The dye molecules (D) absorb light while populating... 

A. I. Ahmed et al. reported the synthesis of coumarins using nanocrystalline sulfated tin oxide S04 /Sn02 catalyst under solvent-free conditions at 120°C.A plausible mechanism for the formation of 7-hydroxy-4-methyl coumarin using synthesized nanosize S-Sn is presented in (Scheme 21) (12JMCCF21).The mechanism can be justified by the discussion presented previously for the similar case (11MI93). 

These cells do not rely on a traditional p-n junction to separate photo-generated charge carriers. Polymer cell materials used include polyester (PET) foil, indium tin oxide (ITO) film, polyethylenedioxythiophene (PEDOT), and aluminum. Nanocrystalline cells use thin film materials and are overlayed on a supporting matrix of conductive polymer or mesoporous metal oxide. 

---