Polysilanes, inks containing the same, and methods for their preparation
are disclosed. The polysilane generally has the formula
H--[(AHR).sub.n(c-A.sub.mH.sub.pm-2).sub.q]--H, where each instance of A
is independently Si or Ge; R is H, --A.sub.aH.sub.a+1R.sub.a, halogen,
aryl or substituted aryl; (n+a).gtoreq.10 if q=0, q.gtoreq.3 if n=0, and
(n+q).gtoreq.6 if both n and q.noteq.0; p is 1 or 2; and m is from 3 to
12. In one aspect, the method generally includes the steps of combining a
silane compound of the formula AH.sub.aR.sup.1.sub.4-a, the formula
A.sub.kH.sub.gR.sup.1'.sub.h and/or the formula
c-A.sub.mH.sub.pmR.sup.1.sub.rm with a catalyst of the formula
R.sup.4.sub.xR.sup.5.sub.yMX.sub.z (or an immobilized derivative thereof)
to form a poly(aryl)silane; then washing the poly(aryl)silane with an
aqueous washing composition and contacting the poly(aryl)silane with an
adsorbent to remove the metal M. In another aspect, the method includes
the steps of halogenating a polyarylsilane to form a halopolysilane; and
reducing the halopolysilane with a metal hydride to form the polysilane.
The synthesis of semiconductor inks via dehydrocoupling of silanes and/or
germanes allows for tuning of the ink properties (e.g., viscosity,
boiling point, and surface tension) and for deposition of silicon films
or islands by spincoating, inkjetting, dropcasting, etc., with or without
the use of UV irradiation.