Understanding the S-shape behavior of illuminated IV in bilayer organic solar cells

This paper attempts to understand the underlying physics associated with the S-shape behavior of the illuminated IV in bilayer organic solar cells. A comprehensive charge transport model was developed to quantitatively study the role of three major hypotheses for S-shape IV behavior: the work function of electrodes, the bulk recombination, and the recombination at the PV interface. Work function of the front and back electrode, recombination lifetime in the bulk of acceptor and donor layers, and the recombination velocity for electrons, holes and excitons at the donor/acceptor interface are used as the sweep parameters to develop a comprehensive quantitative understanding of the effect of sweep parameters on the IV behavior and its shape. The results from this simulation along with the experimental results from the relevant literature will be utilized to understand the physics behind the S-shape behavior of the illuminated IV in the bilayer organic solar cells.