First-principles studies of electronic, transport and bulk properties of pyrite FeS2

Abstract

We present results from first principle, local density approximation (LDA) calculations of electronic, transport, and bulk properties of iron pyrite (FeS2). Our non-relativistic computations employed the Ceperley and Alder LDA potential and the linear combination of atomic orbitals (LCAO) formalism. The implementation of the LCAO formalism followed the Bagayoko, Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF). We discuss the electronic energy bands, total and partial densities of states, electron effective masses, and the bulk modulus. Our calculated indirect band gap of 0.959 eV (0.96), using an experimental lattice constant of 5.4166 Å, at room temperature, is in agreement with the measured indirect values, for bulk samples, ranging from 0.84 eV to 1.03 ± 0.05 eV. Our calculated bulk modulus of 147 GPa is practically in agreement with the experimental value of 145 GPa. The calculated, partial densities of states reproduced the splitting of the Fe d bands to constitute the dominant upper most valence and lower most conduction bands, separated by the generally accepted, indirect, experimental band gap of 0.95 eV.

Modulation of optical absorption in m-Fe1−xRuxS2 and exploring stability in new m-RuS2

“…Transition metal dichalcogenides (TMDC’s) have gained extensive research interest in the field of material sciences due to their photocatalytic and high optical absorption which are beneficial for the development of high power photovoltaic solar cells 1 . Among the members of TMDCs, pyrite FeS 2 (p-FeS 2 ) looks promising not only because of its remarkable optical absorption coefficient (α≈10 5 cm −1 in visible energy region) and photocurrent quantum efficiency (> 90%) 2 , 3 , but also due to its diverse features such as, suitable energy band gap ~ 0.95 eV, nontoxicity, cost-effectiveness and abundance 4 – 6 in nature. Despite, several research works 7 – 9 have reported suboptimal photovoltaic performance of p-FeS 2 due to its low band gap.…”

Theoretical Study of Ternary CoSP Semiconductor: A Candidate for Photovoltaic Applications

“…This latter feature is common to compound, as well as the whole trend of the bands distribution which seems very similar (see refs. []). These similarities could be attributed to the fact that both compounds are isostructural, but more important are isoelectronic, that is, they have the same valence configuration.…”

“…We just recall that it is a semiconductor, with an indirect band gap and most of the experimental measurements give ≈0.9 eV (a good account of the computed and measured gap is reported in ref. []). In a previous work on alloys, our GGA calculations gave eV, much smaller than experimental value.…”

Unraveling complex magnetism in two-dimensional FeS$_2$

“…Bulk FeS 2 is a paramagnetic material with a band gap around 0.9 eV, which makes it a promising candidate for applications in the field of photovoltaic and photoelectron chemical cells [20][21][22]. FeS 2 is similar to MnSe 2 [14], which has been demonstrated to have high-temperature ferromagnetism down to monolayers whereas their bulk counterparts are low-temperature antiferromagnetic materials.…”