Collaborative Research: Photolytic CVD Processes for Thermally Sensitive Substrates

University Of Texas At Dallas, Richardson TX

Investigators

Abstract

Non-Technical Summary: Next-generation electronic devices using plastics and other flexible materials have the potential for revolutionary societal benefits in medicine, sustainable energy and information technology. Development of reliable, widely applicable methods to apply metals to heat-sensitive materials such as organic and polymer thin films will be an important step in the production of these devices. This project is developing methods to use light as an energy source to drive placement of metal contacts on heat-sensitive materials. Because the metal can be applied in patterns, the method could eventually be used to print circuits on flexible electronics. Participation in this research provides graduate students with technical and collaborative skills valuable in either academic or industrial careers. Undergraduate researchers contribute significantly to the proposed work, which encourages them to pursue graduate education in the physical sciences and engineering. To communicate the excitement of science to the general public, participants in the project are involved in public outreach on chemistry and chemistry-based nanotechnology. Technical Summary: This project is developing photolytic chemical vapor deposition (CVD) processes for the selective deposition of metals onto thermally sensitive materials, such as organic thin films. The reliable formation of stable metallic contacts to organic thin films is critical to many technologies from energy harvesting to sensing to organic/molecular electronics. The development of photoassisted low temperature CVD will advance the state-of-the-art in organic electronics by enabling the integration of molecular assemblies into complex devices. In this collaborative project, design and synthesis of ruthenium, platinum and gold complexes as photosensitive CVD precursors is followed by a screening process involving identification of the primary photoprocess, determination of the quantum yield for ligand loss, elucidation of thermal decomposition steps, and modeling reactivity with functional groups on the substrate surface. Promising precursor complexes are subjected to photolytic chemical vapor deposition experiments with self-assembled monolayers (SAMs) as model substrate systems. SAMs are used as the substrates because they have highly organized structures with a uniform density of terminal organic functional groups that will allow the quantitative investigation of the precursor-molecule interactions. Further, SAMs can be easily patterned to produce multifunctional surfaces, which are used to determine the selectivity of the deposition reactions.