The development of solar cells is driven by the need for clean and sustainable energy. Organic and dye sensitized cells (DSC) are considered as promising alternatives for traditional single crystal silicon cells, particularly for large area, low cost applications. However, the efficiency of such cells is still far from the theoretical limit.
First-principles quantum mechanical simulations may be used for computer-aided design of new materials, material combinations, and nano-structures for more efficient organic and dye-sensitized cells. To this end, it is important to obtain an accurate description of the electronic structure, including the fundamental gaps and energy level alignment at interfaces. This requires a treatment beyond ground-state density functional theory (DFT). Within the framework of many-body perturbation theory (MBPT), these properties may be calculated using the GW approximation, where G is the one-particle Green's function and W is the dynamically screened Coulomb potential.
In this talk I will provide an introduction to GW methods and demonstrate their applications to the components of organic and dye-sensitized solar cells: TiO2 clusters , organic semiconductors [2,3], dyes [4,5], and dye-sensitized TiO2 clusters [6,7].
References:  N. Marom, M. Kim, and J. R. Chelikowsky, Phys. Rev. Lett. 108, 106801 (2012)  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, X. Ren, J. E. Moussa, J. R. Chelikowsky, and L. Kronik, Phys. Rev. B 84, 195143 (2011)  E. Salomon, P. Amsalem, N. Marom, M. Vondracek, L. Kronik, N. Koch, and T. Angot, Phys. Rev. B 87 075407 (2013)  N. Marom, J. E. Moussa, X. Ren, A. Tkatchenko, and J. R. Chelikowsky, Phys. Rev. B 84, 245115 (2011)  N. Marom, T. Körzdörfer, X. Ren, A. Tkatchenko, and J.R. Chelikowsky, to be published