Photoconductivity, silicon polymers

The.unusual ability of poly(silanes) to absorb UV light led to the demonstration that Asp5-doped poly(silastyrene) is a semiconductor. The band gap in common silane polymers is about 4eV in contrast to a value of almost 8eV for carbon chains. Conducting and photoconducting properties have been studied. Only holes were found mobile (mobilities of 10 cm V s at 20°C) and it appears hole transport occurs via the a electronic states of the silicon backbone rather than hopping between chain substituents. 

Polymers with silicon-silicon single bonds in the backbone have been known for some time. It was only within the last 10-15 years, however, that high molecular weight materials were developed [165]. Behind the current interest in these materials is a realization that they have various potential applications. These are in ceramic fibers [166], in microlithography [165, 167], in photoconduction [168], and as nonlinear optical materials [169],... 

On the other hand, formation of photorefi active silicone composite with good performance was reported A carbazole-substituted polysiloxane that was sensitized by 2,4,7-trinitro-9-fluorenone was used as a photoconducting medium and l-[4-(2-nilrovinyl)phenylpiperidine was added as an optically nonlinear chromophore. The photorefractive property of polymer was determined by diffraction efficiency using a 100 pm-thick film. The maximum diffraction efficiency (rj max) of 71% was obtained at the electric field of 70 V/pm. 

Saharil F et al (2013) Dry adhesive bonding of nanoporous inorganic membranes to microfluidic devices using the OSTE(+) dual-cure polymer. J Micromech Microeng 23 025021 Searson PC et al (1991) Porous sihcon membranes. Appl Phys Lett 59(7) 832 Sedlaclk R et al (1995) Photoconductivity study of self-supporting porous silicon. Thin Solid Films... 

This chapter will deal with conducting systems, which are produced from the reaction of the silicon and germanium polymers with various dopants. Therefore, photoconducting polymers will not be involved. We shall also limit our attention to the polymers that have the silicon and germanium atoms in the main chain, but not in the side-group. 

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