$Ab initio$ design for optimizing the efficiency of PCBM-P3HT solar cells.
Menichetti G., Colle R., Grosso G.
By means of $ab initio$ calculations, including long-range (vdW) interactions, we studied the electronic and optical properties of the heterointerface between a single layer of PCBM molecules adsorbed on a clean P3HT crystalline polymer. These are the best candidates as organic materials for high power conversion efficiency organic photovoltaic cells. We focus on the evaluation of the near-gap electronic band structure in the PCBM-P3HT complex while the optical spectrum is useful to evidence the nature of the electronic states. We then analyze the effect of uniaxial stress on the band alignment, suggesting a way to engineer the efficiency of a P3HT-PCBM--based solar-cell device.