The primary focus of previous electronic innovation has been the miniaturization of components. The industry has continued to double the number of transistors in a constant area approximately every 18 months, as presciently predicted by Moore’s Law in 1965. This was a prediction made when devices were many microns in size. The current generation is 50 nm. However, if one continues to project this size reduction over the next few years, one approaches limits due to fluctuations, fabrication processes, and eventually to molecular size. Nanoelectronics may be the answer.
One of the great challenges is the conductance spectroscopy of a nanoscale electrical circuit. In such a circuit, a quantum nanoscale system (a molecule, a quantum dot or a molecular assembly) is assembled between two electrodes, with or without a third gate electrode. The current/voltage characteristics of the nanoscale circuit are examined, under different conditions including temperature, solvent, gating, and others. This is conductance spectroscopy, and within the last decade it has become an intensely investigated subject around the world.
Conductance spectroscopy provides fundamental insight into how nanoscale quantum systems couple with non-equilibrium continuous fields. More specific applications involve the areas of ultra sensitive sensors, molecular actuators, or elements of more complex nanoscale circuitry.
A fundamental theoretical realization concerning these structures is that, because of the continuum nature of the electrodes, it is necessary to use nonequilibrium transport methods to understand how charge is transported across these nanoscale junctions. Ohm’s law usually fails! Development and application of such codes have been a significant effort for Institute researchers, and several key insights have been gained and published.
New tools for quality control are also being investigated. Institute researchers recently developed a technique called Scanning Near-Field Ultrasound Holography (SNFUH), which allows investigation of shapes and features underneath opaque materials. This “x-ray like” technique is non-destructive, and can indicate the location of a damaged or incomplete component. The two-dimensional whole-field view provides a complete picture, rather than the limited view provided by more conventional approaches, cutting along a single dimension where localized errors can be missed.
Institute researchers are also developing materials that incorporate transistors in hybrid organic-inorganic thin films. These transparent circuits can be developed into new display technologies on helmet visors or vehicle windows. The “invisible” electronics are close to replicating the high level of performance typically achieved by standard opaque electronics. New display strategies can now be considered, such as multiple layers that may be stacked together providing text and/or images that can be shown floating in space.
Nanoelectronics focuses on reducing the size of typical electronic components, and transitioning the environment of computational technologies. These two strategies act in concert with one another to create innovative new products, solutions, and scientific discovery that will foster the next generation of computational and electronic research exploration.