Charge separation in organic solar cells: Effects of Coulomb interaction, recombination and hole propagation

¹ Research Institute for Applied Physics and Astronomy, University of Tabriz - 51666-14766 Tabriz, Iran
² Institut NÉEL, CNRS and Université Grenoble Alpes - F-38042 Grenoble, France
³ School of Electrical, Electronic and Computer Engineering, The University of Western Australia WA 6009 Crawley, Australia

^(a) didier.mayou@neel.cnrs.fr

Received: 17 December 2015
Accepted: 20 July 2016

Abstract

Bulk heterojunction (BHJ) organic photovoltaic cells are analysed within a simple efficient model that includes the important physical properties of such photovoltaic systems. In this model, in contrast with most of the previous studies, we take into account the motion of both the electron and the hole in the separation process at the donor-acceptor interface. We theoretically examine the exciton dissociation yield under the influences of charge Coulomb interaction and non-radiative recombination. We find that the electron-hole local Coulomb attraction and charge carriers' coupling parameters play an important role in the system performance and in the optimal energy conversion efficiency of the BHJ photocell. We show that the fixed-hole models tend to underestimate the yield.