Midwest Research Institute

Douglas L Schulz

David Samuel Ginley

Calvin J Curtis

Martin Pehnt

A process for forming an electrical conductor on a substrate is provided, consisting essentially of providing an ink comprised of a metallic chelate, printing directly thereon the ink, and decomposing the ink wherein the metal-chelate is converted to a solid metal conductor on the substrate.

Direct printing of thin-film conductors using metal-chelate inks

The present invention provides a process for etching a corrosion layer, such as oxide or hydroxide, from and concomitantly forming a passivating layer on the surface of metallic nanoparticles. A reaction mixture is prepared by dispersing sodium hexafluoroacetylacetonate (Na(hfa)) and a metallic particle powder having oxide or hydroxide corrosion layers in hexane solvent. The mixture is allowed to react for a time sufficient to etch the oxide or hydroxide groups from the particulate surface and passivate the surfaces with (hfa). Hexane may be evaporated from the mixture and any excess Na(hfa) separated from the reaction mixture by sublimation or rinsing with a polar aprotic solvent. In an embodiment of the present invention, aluminum particles are first etched and passivated and then used to form ohmic contacts with p-type silicon. This etching/passivation improves the electrical properties of the contact.

Passivating etchants for metallic particles

A colloidal suspension comprising metal chalcogenide nanoparticles and a volatile capping agent. The colloidal suspension is made by reacting a metal salt with a chalcogenide salt in an organic solvent to precipitate a metal chalcogenide, recovering the metal chalcogenide, and admixing the metal chalcogenide with a volatile capping agent. The colloidal suspension is spray deposited onto a substrate to produce a semiconductor precursor film which is substantially free of impurities.

Solution synthesis of mixed-metal chalcogenide nanoparticles and spray

A process for the preparation of a semiconductor film. The process comprises depositing nanoparticles of a semiconductor material onto a substrate whose surface temperature during nanoparticle deposition thereon is sufficient to cause substantially simultaneous fusion of the nanoparticles to thereby coalesce with each other and effectuate film growth.

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Billerica, MA, United States of America

Douglas L Schulz