| AVS 58th Annual International Symposium and Exhibition | |
| Plasma Science and Technology Division | Wednesday Sessions |
| Session PS+SE-WeM |
| Session: | Atmospheric Plasma Processing and Micro Plasmas |
| Presenter: | Mohan Sankaran, Case Western Reserve University |
| Correspondent: | Click to Email |
Large-scale, low-pressure plasmas play an essential role in the processing of materials for a wide-range of applications including integrated-circuit (IC) manufacturing. In recent years, new challenges have arisen for these top-down approaches to materials processing. Advanced electronic devices will be comprised of nanomaterials such as nanoparticles and carbon nanotubes that cannot be fabricated by current plasma technology because of limitations associated with photolithography. In addition, emerging applications in sensors, energy, and medicine require nanomaterials that must be prepared from the “bottom-up” and assembled into macroscale structures. The aim of our research is to develop a new class of plasmas, termed microplasmas, for nanomaterials synthesis and assembly.
Microplasmas are electrical discharges formed in geometries where at least one dimension is less than 1 mm. As a result of their pD scaling (p is the gas pressure and D is the smallest dimension), microplasmas operate stably at atmospheric pressure. These properties open up unique opportunities for nanomaterials synthesis and assembly. For example, vapor-phase metal-organic precursors can be dissociated near ambient conditions to homogeneously nucleate metal [1] and alloyed [2] nanoparticles. The formation of well-defined metal nanoparticles in the gas phase allows direct introduction of these materials as catalysts for chiral-enriched carbon nanotube growth [3]. Recently, we have also coupled microplasmas with liquids to electrochemically synthesize nanoparticles from aqueous metal salts [4]. By extending this strategy to thin films, microscale patterns of nanoparticles are fabricated in a single step [5]. In this talk, I will discuss these topics in detail, highlightingthe advantages of microplasma-based systems for the synthesis of well-defined nanomaterials at various length scales.
1. W-H. Chiang and R. M. Sankaran, Appl. Phys. Lett. 91, 121503 (2007).
2. P. A. Lin and R. M. Sankaran, in review.
3. W-H. Chiang and R. M. Sankaran, Nat. Mater. , 882 (2009) .
4. C. Richmonds and R. M. Sankaran, Appl. Phys. Lett. , 131501 (2008).
S. W. Lee, D. Liang, X. P. A. Gao, and R. M. Sankaran, Adv. Func. Mater., available online: doi: 10.1002/adfm.201100093.