Molecular Nanoelectronics: Simulation from Molecules to Circuits

Purdue Research Foundation, West Lafayette IN

Investigators

Abstract

The objective of the proposed research is to establish a collaborative team of experts from the chemistry of molecular electronics, the physics of electronic conduction at the molecular scale, advanced electronic structure, transport properties and experimental agreement, and silicon device and circuits technology to address the challenges of electronics at the quantum scale. This will require modeling and simulation involving multiple length and energy scales, starting from atomic Hamiltonians and going to complex circuits. Leveraging advances in molecular self-assembly, interfacial control, and the use of scanning probes, we will examine molecular bridges between bulk contacts, and relate the general features observed in experiments to simulations which compute the Landauer conductance from the Green's function of the molecule coupled to bulk, metal leads. Very recent, interesting, and potentially useful, reversible switching characteristics that have been observed will be analyzed theoretically. The systems typically consist of hard contacts (semiconductors or metals) and soft molecules that may exhibit dynamic structure modification. The objectives of this multi-disciplinary, small group effort are: i) to understand the physical and electronic structure and vibronic interactions of molecular bridges between hard contacts, ii) to develop a theoretical understanding of the interesting nonlinear I-V characteristics of molecules that are now being observed and to relate them to the structure of the molecule, iii) to devise methods for extracting physics-based, circuit models from the Hamiltonian of molecular electronic devices and iv) to use this knowledge and the simulation tools developed to identify molecular structures that are promising from a device and circuits perspective. The development of an understanding of how to relate electronic device and circuit function to molecular structure is the key objective of the proposed research. Other important components and products of this work include: i) the development of a set of 'community codes' for molecular nanoelectronics that emphasize the structure/function relationship of molecular devices and that connect them to the macroscopic world of circuits and systems, ii) a methodology to allow a researcher to suggest a particular structure, electrodes, and interfacial linkages, predict the electrical performance of the device, and to extract a circuit model, iii) a unique software infrastructure, The Computational Electronics Hub, that will permit users to access and operate simulation tools through a WWW browser, iv) a set of courses that will be enriched and expanded by this multidisciplinary effort, v) close interactions with leading experimental efforts in academia (Reed at Yale) and industry, vi) a partnership with the NIST group to provide expertise in advanced molecular electronic structure methods, vii) collaboration with international centers, particularly the Central University of Venezuela, viii) A high-school level teaching module in the Materials World Modules program, and ix) close interactions with the Semiconductor Research Corporation and with individual semiconductor companies to bring ideas and approaches of self-assembled molecular electronics to the electronics industry.