The Interface Problem: A Many-Body Perturbation Theory Perspective
When two materials form an interface, new properties and functionalities emerge that are possessed by neither material separately. The active region of an electronic device typically involves one or more interfaces. Understanding and predicting the properties of these interfaces is essential for improving device performance. To achieve a correct description of the energy gaps and level alignment at an interface, one must account for electronic relaxation and dynamic screening effects, which are absent from density functional theory (DFT). Green’s function based many-body perturbation theory is often used for this purpose within the GW approximation, where G is the one particle Green’s function and W is the dynamically screened Coulomb interaction. In this talk, I will introduce the hierarchy of GW methods, from the non-self-consistent G0W0 scheme to fully self-consistent GW, and examine their performance in the context of the dye-TiO2 interface, found in the active region of dye sensitized solar cells.
T. Körzdörfer and N. Marom, PRB 86, 041110(R) (2012)
N. Marom, F. Caruso, X. Ren, O. Hofmann, T. Körzdörfer, J. R. Chelikowsky, A. Rubio, M. Scheffler, and P. Rinke, PRB 86 245127 (2012)
N. Marom, T. Körzdörfer, X. Ren, and J.R. Chelikowsky, to be published
F. Caruso, X. Ren, N. Marom, M. Scheffler, and P. Rinke, to be published