High-throughput identification of materials for silicon tandem solar cells

High-throughput ab initio calculations are employed to identify the most promising materials for Si tandem solar cells. Starting with the Materials Project database of more than 131 000 materials, we evaluate the relevant properties of thermodynamic stability, lattice mismatch with silicon, band gap, effective mass, optical absorption coefficient and dynamic stability. The identified 11 optimal candidates represent a variety of material chemistries with oxides, pnictogenides, and chalcogenides included. Among them, perhaps the most promising is Cu2ZnSiSe4, which has almost ideal properties for all physical criteria and is composed of relatively earth-abundant constituents.