BCCMS  /  CMS  /  Research  /  SILaN

Surfaces, Interfaces, Layers, and Nanostructures

(Group of Electronic Materials)

Movie about the dynamical simulation of an O2 molecule interacting with the SiC/SiO2 interface. (Click on the picture to see the movie.)

Materials are traditionally divided into the groups of structural and functional materials. The surface of the former (mostly metals and ceramics) have to withstand mechanical wear and corrosion, but in many cases are required to adhere to other materials. All these phenomena can be traced back to atomic processes at the surface. The surface of the functional materials (mostly semiconductors) can have a detrimental effect on the performance, so they require chemical and/or electrical passivation: a process relying on the meticulous control of atomic reactions. However, in many cases the surface itself is the basis of the functionality (like in electron emitters, sensors, or in heterogeneous catalysis). In addition, the technical importance of layer structures is continuously increasing and their deposition happens mostly through the interaction of atoms of the gas phase with the substrate surface. Considering all this, the understanding of atomic processes at surfaces, interfaces and in layer structures is becoming increasingly important in all areas of technology. Due to the sensitivity limits of experimental methods, computer simulations based on quantum mechanics is a very valuable tool in the learning process. Recent developments in materials science aim at nanotechnologies: mostly by nanostructuring surfaces or creating ultra-thin layer structures. In this field, computer simulations are playing a pioneering role.

Computational materials science of surfaces, interfaces, layers, and nanostructures (SILaN) in traditional (mostly inorganic) materials are an important part of the activities in the BCCMS. Depending on the task, efficient semi-empirical (DFTB) and high quality first principles methods (DFT and beyond) are applied for quasistatic and dynamic simulations. Based on the experience gained by studying bulk diamond and diamond like carbon layersearlier, we are now investigating the surfaces and defects of ultra-nano-diamonds for biomedical and magnetometric applications. Also, the years spent on finding the appropriate theoretical methods (beyond standard LDA/DFT) for wide band gap semiconductors, like SiC, is bringing now fruit in our study of TiO2, a material with "all-round" applications: from water splitting and hydrogen storage, through photocatalytic air and water purification, to  electrochemical solar cells and transparent conductors. 

Investigators in the group

Presently active cooperations

  • Adam Gali, Budapest University of Technology and Economics, Hungary