| AVS 57th International Symposium & Exhibition | |
| Plasma Science and Technology | Monday Sessions |
| Session PS2-MoA |
| Session: | Atmospheric Plasma Processing and Micro Plasmas |
| Presenter: | R.M. Sankaran, Case Western Reserve University |
| Correspondent: | Click to Email |
Large-scale, low-pressure plasmas play an essential role in the manufacturing of integrated circuits that are now ubiquitous in consumer electronics. In recent years, new challenges have arisen for these top-down approaches to materials processing. Future electronic devices will incorporate nanoscale materials such as nanoparticles, carbon nanotubes, and silicon nanowires that cannot be fabricated by current plasma technology because of limitations associated with photolithography. In addition, emerging applications in sensors, energy, and medicine require materials that must be prepared from the “bottom-up”. The aim of our research is to develop a new class of plasmas, termed “microplasmas”, for nanomaterials synthesis.
Microscale plasmas or microplasmas are a special class of electrical discharges formed in geometries where at least one dimension is less than 1 mm. As a result of their unique scaling, microplasmas operate stably at atmospheric pressure and contain large concentrations of energetic electrons (1-10 eV). These properties are attractive for a range of nanomaterials applications. Vapor-phase metal-organic precursors can be dissociated at ambient conditions (i.e. room temperature and atmospheric pressure) to homogeneously nucleate metal1 and alloyed2 nanoparticles. The formation of metal nanoparticles in the gas phase allows direct introduction of these materials as catalysts for carbon nanotube and silicon nanowire growth3. Recently, we have also coupled microplasmas with liquids or polymeric films to nucleate nanoparticles from metal ions4. In this talk, I will discuss these topics in detail, highlighting the advantages of microplasma-based systems for the synthesis of well-defined nanomaterials.
1. W-H. Chiang and R. M. Sankaran, “Microplasma synthesis of metal nanoparticles for gas-phase studies of catalyzed carbon nanotube growth,” Appl. Phys. Lett., Vol. 91, 121503 (2007).
2. W-H. Chiang and R. M. Sankaran, “Synergistic effects in bimetallic nanoparticles for low temperature carbon nanotube growth,” Adv. Mater., Vol. 20, 4857 (2008).
3. W-H. Chiang and R. M. Sankaran, “Linking catalyst composition to chirality distributions of as-grown single-walled carbon nanotubes by tuning Ni Fe nanoparticles,” Nat. Mater., Vol. 8, 882 (2009).
4. C. Richmonds and R. M. Sankaran, “Plasma-liquid electrochemistry: Rapid synthesis of colloidal metal nanoparticles by microplasma reduction of aqueous cations,” Appl. Phys. Lett., Vol. 93, 131501 (2008).