A Gaussian model for recombination via carrier-trap distributions in organic solar cells

So far, the model and the number of parameters that have been used in the literature to describe the recombination mechanism in an organic semiconductor depend on the type of trap distribution assumed. Because using only one particular recombination model could be relevant for the design of a computer algorithm to simulate organic devices, in this work, we analyze and validate a function that could be considered to be a generalization of the classic model of the recombination process via carrier-traps. Our proposal is based on Shockley–Read–Hall model which is extended to include traps in the energy continuum. We show that a Gaussian function could be set through physical parameters to approximate the most common trap distributions in the band gap such as an exponential distribution and traps in a single energy level. The application of this model for the determination of the current density–voltage characteristics of organic solar cells under illumination and in the dark is also demonstrated.