Abstract
Pyrite FeS2 has become the focus of many researchers in thin-film photovoltaics because it has some possibilities in photovoltaics. In this manuscript, we present an experimental and a theoretical study of the electronic structure of pyrite FeS2 alloyed with a small concentration of 1.19% of ruthenium (Fe0.9881RU0.0119S2) by using the Linear Muffin-Tin Orbital Method in the Atomic-Sphere approximation (LMTO-ASA) calculations and the density of states. We observed that the bandgap of FeS2 increases from 0.90508 to 1.21586 eV when we replace similar to 1.19% of the Fe atoms with ruthenium atoms (x = 0.0119 concentration of Ru). We prove that this low concentration of Ru saved the gap states and the electronic and optical properties of FeS2 pyrite. Our calculated electronic bandgap is 1.21586 eV and direct. Our results confirm that the symmetric operation of the space T(6)h (Pa3) saves electronic structure of iron pyrite when alloyed with ruthenium.