ABSTRACT: Since the lab-made synthesis of diamond from 1950s we came a long way from synthesizing bulk diamond from high-pressure high-temperature technique to low-pressure low-temperature CVD technique, which allows us to synthesize this wonder material on a wafer-scale although in the form polycrystalline diamond thin films. By changing the grain size from micron to nanosize, various interesting properties of diamond thin films could be manipulated allowing them to be utilized in the fabrication of novel MEMS/NEMS devices. I’ll discuss some of the work we have done in the past towards fabrication of robust RF-MEMS devices [1-2] and piezoresistive sensors based on diamond nanowires. Another interesting aspect that we have explored recently is regarding the integration of diamond with two dimensional (2D) materials such as graphene, h-BN and MoS2 and formation of heterojunction devices with exceptional performance. Diamond offers multiple unique properties, such as high phonon energy, low trap density, and high thermal conductivity, which make it an ideal substrate for various 2D materials to form heterojunction through Van der Waals interactions. In case of graphene on diamond, we demonstrate very high current density (109 A/cm2) from the fabricated devices . We further demonstrate a novel process to grow large area single and few-layer graphene directly on the diamond thin film on wafer-scale thus eliminating the need for graphene transfer . I’ll also present few highlights of our recent work on the possible formation of p-n junction with p-doped bulk diamond and n-MoS2 layer and fabrication of H-terminated diamond FET devices using h-BN as a dielectric layer. This approach of diamond/2D materials integration offers new opportunities for developing novel nanoelectronic devices on diamond although more work in needed in understanding the mechanism of charge transport at the interface and the effect of surface chemistry on tailoring the performance of these devices. If time permits, I’ll briefly discuss another interesting topic of superlubricity  where we show how combination of graphene and nanodiamond together helps in reducing friction and wear to near zero and its potential impact on the lubrication industry.
Webform for Scheduling a Meeting
BIO: Dr. Anirudha Sumant is a Materials Scientist at Center for Nanoscale Materials, Argonne National Laboratory and leading the research on nanocarbon materials including CVD-diamond, carbon nanotube, graphene as well as other 2D materials. He is a leading expert on energy-efficient systems based on nanocarbon materials. He has more than 25 years of research experience in the synthesis, characterization and developing applications of CVD-diamonds. His main research interests include nucleation and growth mechanism of diamond and other carbon materials, novel synthesis routes, surface chemistry, nanoelectronics, micro/ nano-scale tribology, and micro-nanofabrication. He is the author and co-author of more than 120 peer-reviewed journal/proceedings publications, 2 book chapters, and has 27 granted patents, 15 pending. The list of his awards include four R&D 100 awards, NASA Tech Brief Magazine Award, and three TechConnect National Innovation Awards. He recently co-developed a nanotechnology educational kit “Next Gen STEM kit” for high school students in collaboration with United Scientific Supplies Inc. which is now available to high schools across the nation, that gives students first-hand nanofabrication experience right in the their classroom. He was recognized by Pinnacle of Education Award from Board of Governors of UChicago/Argonne LLC for this achievement. He has presented his research via numerous invited/keynote talks as well as through TEDx talk. His research in diamond and graphene materials helped in the formation of several start-up companies. He is a member of MRS, STLE and AVS.
Research highlights and portfolio: