Moore’s Law is famously known for projecting an increase in computing performance, with the number of transistors in an integrated circuit doubling every two years. As the size of transistors approaches the ultimate limits, new concepts are needed for performance breakthroughs. Molecular electronics aims at developing devices that will complement and eventually supersede current semiconductor technologies. Molecular transport junctions have unique advantages, due to their hybrid solid state-molecular nature and novel interface properties. The variety of possible combinations of molecules and electrodes also permits tailoring the transport properties. Electrically gating charge transport was key to the electronics revolution, but no mechanism currently exists to effectively gate molecular transport junctions. This project will address that gap through a systematic probe of the factors related to electric transport. This will improve the fundamental understanding of these novel devices and enable a new gating mechanism to control electric transport with an unprecedented level of control. This will allow for integration of specific functions into molecular junctions that will enable practical applications. These include bio-photonics and optoelectronic device such as solar cells and LEDs at the single molecule level. This project will train for undergraduate and graduate students in interdisciplinary nanotechnologies that span physics, chemistry and engineering. An introductory course in nanoelectronics will be updated to include the new materials from the project. The PIs will recruit students of different scientific, ethnic, and nationality backgrounds to study science and engineering to foster our next generation scientists and engineers through this project. Students can also participate in related university programs, such as Summer Undergraduate Research Program (SURP), UGA-Louis Stokes Alliances for Minority participation (LSAMP) Program, and the Nanotechnology and Biomedicine REU Site.
This project aims to develop enabling technologies that allow for integration of our recently developed and patented MTBJ systems with optics to probe and control opto-electronic transport in biased single molecule MTBJs through three tasks. The PIs will develop a measuring platform by integrating optical designs into our patented SPM MTBJs that allow the molecule to connect covalently to two electrodes with linker groups, which enables the controlling of the molecule-electrode coupling and aligning the orbitals of conjugated molecules away from the electrodes. Then, they will conduct a systematic study to measure photoconductance where charge carriers in the MTBJs are excited by radiation energy HOMO to LUMO and by the surface plasmons and determine the effect of molecule-electrode contact and molecular conformation on the carrier injection barrier and photon-induced electronic conduction properties. Finally, they will demonstrate a viable single molecule field-effect Raman scattering (FERS) device, a double gated single molecule MTBJ device, with a second electrochemical gating added to the plasma gating. This project will establish a revolutionary new approach using double gating to effectively gate the electrical transport in MTBJs device by exploring the origins of the most important interactions, such as photon-electron, molecule-electrode interactions, being studied in molecular electronics today. The proposed studies are imperative to advancing research in single molecule devices by providing not only the basic knowledge but also necessary skills to develop novel applications. It will also lead to new insights into the interplay between electron transfer and optical properties in single molecule devices, which is critical to many areas, such as photosynthesis and bio-photonics.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
