Two technological problems that we are currently facing are the rapid approach to the fundamental limits of Moore's law with the diminishing size of electronic devices, and the tremendous need for energy storage, particularly related to energy coming from renewable sources. Manuel Smeu's main research interests can be described as employing computational methods to help address these issues.
Due to the shrinking size of electronic devices, their components are too small to be described by Ohm's law, and quantum effects dominate their characteristics. A completely different class of electronic devices is also under development, in which silicon and metal are replaced with molecular analogs. These systems need to be studied at the atomistic level (all atoms and their positions in a system must be known) with techniques that account for the interactions between electrons at the quantum mechanical level. Prof. Smeu's research group develops and employs methods such as the nonequilibrium Green's function technique combined with density functional theory (NEGF-DFT) to investigate the electron transport properties (current, conductance) of such systems. Some examples of previous work by Smeu include studies on: the conductance of the metallic surface of silicon: Si(111)-7×7, the graphyne molecular unit which could be used as a field effect transistor (can turn it on/off), the current through dye molecules which could be controlled with pH., mechanical control over the conductance of a single molecule by distorting its shape or altering how it binds to electrodes.
Another area of research in the Smeu group involves energy storage. Li-ion batteries are widely used today, particularly for portable devices and electric vehicles. However, lithium is expensive and not as abundant as other metals that may also be used in rechargeable batteries. While it is difficult to compete with Li in terms of weight, alternative battery materials may be useful when portability is not a priority, such as for home backup or grid storage. The Smeu group studies such alternative battery technologies with computational techniques that allow for the prediction of voltage, cycling characteristics, stability, and generally in determining ways to improve battery materials.
Other areas of interest include surfaces and their electronic properties, chemical reactions that occur at interfaces, and development of computational methods.
- PhD, McGill University
- Secondary (rechargeable) batteries utilizing multivalent ions
- Molecular and nano-electronics and spintronics
- Surface adsorption properties of materials
- Structural and electronic properties of materials
"Towards graphyne molecular electronics," Z. Li, M. Smeu, A. Rives, V. Maraval, R. Chauvin, M. A. Ratner, and E. Borguet, Nat. Commun. 6, 6321 (2015).
"Hapticity-Dependent Charge Transport through Carbodithioate-Terminated [5,15-Bis(phenylethynyl)porphinato]zinc(II) Complexes in Metal-Molecule-Metal Junctions." Z. Li, M. Smeu, T.-H. Park, J. Rawson, Y. Xing, M. A. Ratner, M. J. Therien, and E. Borguet, Nano Lett. 14, 5493–5499 (2014).
"Molecular Junctions: Can Pulling Influence Optical Controllability?" S. M. Parker, M. Smeu, I. Franco, M. A. Ratner, and T. Seideman, Nano Lett. 14, 4587–4591 (2014).
"Conductivity of Si(111)-(7×7): The Role of a Single Atomic Step," B. V. C. Martins, M. Smeu, L. Livadaru, H. Guo and R. A. Wolkow, Phys. Rev. Lett. 112, 246802 (2014).
"Single-Molecule Sensing of Environmental pH – an STM Break Junction and NEGF-DFT Approach," Z. Li, M. Smeu, S. Afsari, Y. Xing, M. A. Ratner, and E. Borguet, Angew. Chem. Int. Ed. 53, 1098–1102 (2014).