Title: An Efficient Descriptor Model for Designing Materials for Solar Cells,
Abstract: An efficient descriptor model for fast screening of potential materials for
solar cell applications is presented. It works for both excitonic and
non-excitonic solar cells materials, and in addition to the energy gap it
includes the absorption spectrum ($\alpha(E)$) of the material. The charge
transport properties of the explored materials are modeled using the
characteristic diffusion length ($L_{d}$) determined for the respective family
of compounds. The presented model surpasses the widely used Scharber model
developed for bulk-heterojunction solar cells [Scharber \textit{et al.,
Advanced Materials}, 2006, Vol. 18, 789]. Using published experimental data, we
show that the presented model is more accurate in predicting the achievable
efficiencies. Although the focus of this work is on organic photovoltaics
(OPV), for which the original Scharber model was developed, the model presented
here is applicable also to other solar cell technologies. To model both
excitonic and non-excitonic systems, two different sets of parameters are used
to account for the different modes of operation. The analysis of the presented
descriptor model clearly shows the benefit of including $\alpha(E)$ and $L_{d}$
in view of improved screening results.