Motoo Fukushima

Polysilanes as conducting material producers and their application to metal pattern formation by UV light and electroless metallization

This paper describes a novel method for the deposition of gold, silver and palladium colloids on polysilane films by reducing the corresponding metal salt dissolved in alcohol without the use of any other reductants, and an application of the methodology to the pattern formation of copper and nickel metal by palladium-catalyzed electroless metallization on the surface of poly(methylphenylsilane) film, in combination with UV light lithography at 254 nm without the use of any other photoresists.

Conductivity of doped N-carbazolyl-substituted polysilanes

Abstract A series of N -carbazolyl-substituted silane homo- and copolymers has been prepared by Wurtz coupling. Doping with iodine on these copolymer films increases the electrical conductivity to the range 10 −6 –10 −3 S cm −1 . The conductivity depends strongly on the composition of the copolymer; it reaches the maximum value for N -carbazolyl-substituted silane homopolymer. The effects of carbazolyl group on conductivity and charge transport mechanisms in the polymer are discussed.

Effects of dopants and polymer structures on electrical conductivity of organosilicon polymers

Abstract A series of organosilicon polymers comprising disilanylene-phenylene, disilanylene-ethynylene and disilanylene-(bisethynylene-phenylene) chains carrying dibutyl or phenyl and methyl groups as side chains, and polysilanes carrying alkyl, aromatic or heteroaromatic side chains were synthesized. The electrical conductivities of their polymers doped with electron acceptors such as I 2 , FeCl 3 and SbF 5 were measured by using vapor-phase doping. The electrical conductivities of organosilicon polymers doped with I 2 showed a good correlation with the ionization potentials of the original polymers. In contrast, in the case of SbF 5 doping, the degradation of polymers occurred and every polymer gave the same order of conductivity, 10 −4 −10 −3 S/cm. The polymers carrying heteroaromatic substituents gave the higher conductivity by doping with I 2 , while in the case of the polymers carrying phenyl groups, the conductivity was enhanced by doping with FeCl 3 .

Electrical conductivity of organosilicon polymers II: Synthesis and electrical conductivities of iodine-doped polysilanes containing amino groups

Abstract A series of polysilanes containing an N,N -dimethylaminophenyl group and N -pyrrolyalkyl group as in the side chain were prepared by the Wurtz coupling polymerization. The polymerization of N -pyrrolylbutyl or N -pyrrolylhexyl-substituted dichlorosilane with sodium gave successfully the polysilanes with higher molecular weight than 10 5 . The electrical conductivities of I 2 -doped polysilanes were dependent on the chemical structure of the amino side chain. Moreover, by use of excess iodine, the conductivity of the polymer was enhanced. The electrical conductivity of poly[bis(6-( N -pyrrolyl)hexyl]silane] ( 7a ) increased to a maximum value of 8 × 10 −2 S/cm.

Electrical conductivity of organosilicon polymers III: Carrier mobility analysis of iodine-doped polysilane by hall effect measurement

Abstract The Hall effects of two different types of conducting polymers, poly[(6- N -pyrrolylhexyl)hexylsilane] (PSiPy) and poly( N -methylpyrrole) (PMePy) have been studied. Both of the polymers showed electrical conductivity orders of 10 −2 S/cm by I 2 doping. The polysilane, PSiPy, which is a σ-conjugated polymer, has a positive Hall coefficient and the absolute value of carrier mobility is higher by three orders of magnitude than that of the polypyrrole, PMePy, although the conductivities of both polymers are of the same order.