Energy- and Cost- Efficient Manufacturing Employing Nanoparticle Self-Assembly with Continuous Crystallinity

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

Additive solution-based printing of electronic devices with nanoparticle dispersions is technologically attractive and inspires new sensing and information processing technologies. The key impediment for its wider use in nanomanufacturing is the presence of protective organic layer needed for their stabilization that hampers the charge transfer between nanoparticles. Its resolution has had considerable academic success but new strategies in this direction are needed in order to reduce the cost, energy requirements, improve its scalability, and alleviate environmental concerns. Realization of their low-temperature self-assembly into films with continuous crystallinity and competitive electrical properties will benefit energy storage/harvesting technologies, optoelectronics, and wearable health monitoring devices. The use of earth-abundant materials can potentially open different areas of applications in 'smart buildings' and agriculture that are expected to have a wide ranging ripple effect and contribute to improving the sustainability of the US economy. Novel teaching and learning programs will engender the next generation of innovators with a fundamental understanding of nanotechnology and the technological thresholds for nanomanufacturing, allowing new and creative devices to be developed. To achieve the objective of forming films with continuous crystallinity and competitive electrical properties, the projected method will take advantage of the ability of nanoparticles to self-assemble following the oriented attachment mechanism. This recently discovered technique leads to the self-orientation of the crystal lattices at their boundaries, which should greatly increase conductivity. This project will focus on the realization of oriented attachment for earth-abundant nanoparticles exemplified by the n-type semiconductor Cu2S. This material is attractive for nanomanufacturing not only because of its environmentally benign nature and low cost, but also for its promising electronic, plasmonic, and ion intercalation properties. Resolution of practical and fundamental issues surrounding the charge transport dilemma of solution-processed nanoparticle devices is central to this study. The findings expected for Cu2S can be extended to other device-relevant semiconductors, such as FeS2. Within three years, transition from basic understanding of self-assembly processes of Cu2S nanoparticles to crafting highly conductive films and nanomanufactured devices exemplified by lithium battery cathodes is expected.