Computational Modeling of Novel Bulk Materials for the Intermediate-Band Solar Cells.

Research communities have been studying materials with intermediate bands (IBs) in the middle of the band gap to produce efficient solar cells. Cells based on these materials could reach theoretical efficiencies up to 63.2%. In this comprehensive study, we investigate by means of accurate first-principle calculation the electronic band structure of 2100 novel compounds (bulk materials) to discover whether the IB is present in these materials. Our calculations are based on the density functional theory, using the generalized-gradient approximation for exchange and correlation terms and focusing on the band structure, the density of states, and the electron effective masses of the structures in the database. The IB structures are obtained by adding metallic or semimetallic atoms in the bulk material. By means of these calculations, we have clearly identified a number of compounds that may having high potential to be used as photovoltaic materials. We present here the numerical results for 17 novel IB materials, which could theoretically prove to be suitable for photovoltaic applications.