A Multidisciplinary Approach to Silicon Diamondoids for Molecular Electronics
Abstract
This proposal seeks funding for equipment that will enable the development of silicon diamondoids as materials for electronic transport applications. Silicon diamondoids are atomically nanoclusters of the silicon semiconductor that may be conceived as the smallest silicon nanocrystals. We are running into a fundamental physical limit into how small we can make silicon-based electronics that is intrinsic to the top-down silicon manufacturing approach. Our approach instead seeks to develop silicon electronics from the bottom-up, where molecular silanes are stitched together into silicon nanoelectronics using rational inorganic chemical synthesis. The synthesis and measurement of these compounds has received interest from the AFOSR’s Organic Materials Chemistry Program, particularly to develop chemically doped silicon diamondoids, larger diamondoid structures, and characterize quantum electronic transport in sila-diamondoids with the scanning tunneling microscopy break-junction (STM-BJ) approach. Our program is interdisciplinary and relies on high-level synthesis, structural characterization, and electronic characterization techniques towards the singular goal of establishing structure-quantum transport relationships in silicon diamondoid clusters. Accordingly, the PI seeks to obtain state-of-the-art equipment across these three technical areas for the united goal of creating a stronger feedback loop between synthesis, structural characterization, and transport measurements. The chief piece of equipment requested is a STMBJ apparatus that is capable of performing measurements under inert atmospheres. While the PI has built an STM-BJ setup that works under ambient conditions, it is limited in the types of experiments it can conduct. An inert atmosphere STM-BJ setup would enable the measurement of- (1) moisture-sensitive silicon diamondoids, (2) air-sensitive silicon diamondoids, (3) molecules with air-sensitive electrodes (palladium, iron, silver, nickel) that will enable us to explore strategies for decreasing contact resistance and measuring spin-polarized transport. This measurement setup and its ensuing new experiments would remove limitations for how ambitious we can be in our projects. Next, we request an atmospheric solids analysis probe (ASAP) attachment that will be an add-on to an existing high-resolution mass spectrometer in UC Riverside’s Analytical Chemistry Facility. This technique has been the only one that allows us to characterize the masses of our diamondoids. Our current solution is to send these materials to other universities, which is inefficient both in cost and turnaround time. The third and fourth pieces of equipment are enabling chemical synthesis equipment that will increase the throughput of our work and explore new routes to the proposed diamondoid molecules. A Kugelrohr apparatus is requested for the large-scale isolation of air and moisture-sensitive materials that are otherwise difficult to purify. This piece of equipment will allow us to get to our final products in much shorter timescales. A Retsch Ball Milling Mixer is requested, as recent work has shown the massive yet transient mechanical impact can allow challenging isomerizations to surmount activation barriers that are inaccessible by other means. This equipment may allow us to make silicon diamondoids that cannot be accessed through solution-phase Lewis acid catalysts. The requested equipment will facilitate access to atomically precise silicon nanocrystals for optical, optoelectronic, and quantum electronic applications that are not accessible by any other means. These materials have already shown unusual quantum transport phenomena, and the proposed equipment will broadly expand our capabilities to study these effects in more detail.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 29, 2024
- Source ID
- FA95502310192
Entities
People
- Timothy A Su
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of California Regents