High molecular weight polysilanes are prepared using highly non-chain-transferring solvents. Certain alloys of sodium can also be used to advantage with such solvents. The high molecular weights are achievable even in the commercially preferred "normal" addition procedure.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. application Ser. No. 06/851,713, filed Apr. 14, 1986, now abandoned and a continuation-in-part of PCT/US87/00850, filed Apr. 14, 1987, now U.S. application Ser. No. 07/327,195, filed Oct. 14, 1988, the disclosures of all of which being entirely incorporated by reference herein.
In a process for preparing a polysilane from a diorganodihalosilane and an alkali metal, a low molecular weight polysilane results from the process as a by-product. The low molecular weight polysilane is further reacted with an alkali metal for conversion into a high molecular weight polysilane.
Polymer materials are described, which are formed by polymerization of monomer mixtures containing at least one compound of the formula I wherein R is selected from the group consisting of hydrogen, unsubstituted alkyl, substituted alkyl, unsubstituted aryl and substituted aryl; A is a polyvalent moiety; and x is 2-4. Methods for preparation of polymers derived from monomer mixtures consisting essentially of polyvalent polysilanes, as well as mixtures of polysilanes with monovalent monosilanes, are also described.
A method of making hydrogenated Group IVA compounds having reduced metal-based impurities, compositions and inks including such Group IVA compounds, and methods for forming a semiconductor thin film. Thin semiconducting films prepared according to the present invention generally exhibit improved conductivity, film morphology and/or carrier mobility relative to an otherwise identical structure made by an identical process, but without the washing step. In addition, the properties of the present thin film are generally more predictable than those of films produced from similarly prepared (cyclo)silanes that have not been washed according to the present invention. The present invention advantageously provides semiconducting thin film structures having qualities suitable for use in electronics applications, such as display devices or RF ID tags, while enabling high-throughput manufacturing processes that form such thin films in seconds or minutes, rather than hours or days as with conventional photolithographic processes.
Compositions, inks and methods for forming a patterned silicon-containing film and patterned structures including such a film. The composition generally includes (a) passivated semiconductor nanoparticles and (b) first and second cyclic Group IVA compounds in which the cyclic species predominantly contains Si and/or Ge atoms. The ink generally includes the composition and a solvent in which the composition is soluble. The method generally includes the steps of (1) printing the composition or ink on a substrate to form a pattern, and (2) curing the patterned composition or ink. In an alternative embodiment, the method includes the steps of (i) curing either a semiconductor nanoparticle composition or at least one cyclic Group IVA compound to form a thin film, (ii) coating the thin film with the other, and (iii) curing the coated thin film to form a semiconducting thin film. The semiconducting thin film includes a sintered mixture of semiconductor nanoparticles in hydrogenated, at least partially amorphous silicon and/or germanium. The thin film exhibits improved conductivity, density, adhesion and/or carrier mobility relative to an otherwise identical structure made by an identical process, but without either the semiconductor nanoparticles or the hydrogenated Group IVA element polymer. The present invention advantageously provides semiconducting thin film structures having qualities suitable for use in electronics applications, such as display devices or RF ID tags, while enabling high-throughput printing processes that form such thin films in seconds or minutes, rather than hours or days as with conventional photolithographic processes.
Compositions, inks and methods for forming a patterned silicon-containing film and patterned structures including such a film. The composition generally includes (a) passivated semiconductor nanoparticles and (b) first and second cyclic Group IVA compounds in which the cyclic species predominantly contains Si and/or Ge atoms. The ink generally includes the composition and a solvent in which the composition is soluble. The method generally includes the steps of (1) printing the composition or ink on a substrate to form a pattern, and (2) curing the patterned composition or ink. In an alternative embodiment, the method includes the steps of (i) curing either a semiconductor nanoparticle composition or at least one cyclic Group IVA compound to form a thin film, (ii) coating the thin film with the other, and (iii) curing the coated thin film to form a semiconducting thin film. The semiconducting thin film includes a sintered mixture of semiconductor nanoparticles in hydrogenated, at least partially amorphous silicon and/or germanium. The thin film exhibits improved conductivity, density, adhesion and/or carrier mobility relative to an otherwise identical structure made by an identical process, but without either the semiconductor nanoparticles or the hydrogenated Group IVA element polymer. The present invention advantageously provides semiconducting thin film structures having qualities suitable for use in electronics applications, such as display devices or RF ID tags, while enabling high-throughput printing processes that form such thin films in seconds or minutes, rather than hours or days as with conventional photolithographic processes.
