Augmenting the band gap of iron diselenide pyrite via ruthenium alloy integration

The study aimed to enhance the properties of thin FeSe2 films by incorporating ruthenium through spray pyrolysis. Films were deposited on pre-heated glass substrates and subjected to controlled heating in a selenium-rich environment. X-ray diffraction analysis confirmed the presence of FeSe2 phase. Films with specific ruthenium ratios showed notable improvements in optical attributes, including increased absorption coefficient and a higher direct band gap, aligning with desired values for photovoltaic applications. Hall Effect measurements revealed N-type conductivity with varying concentrations and temperature-dependent electrical properties. The results highlight the efficacy of ruthenium as a promising alloying candidate for developing photovoltaic materials, emphasizing the versatility of the produced films across multiple domains

Impact of alloying iron pyrite by ruthenium on its band gap values and its insight to photovoltaic performance

In pursuit of augmenting the band gap value of thin films composed of FeS2 Pyrite, our study encompasses both theoretical and experimental investigations. Specifically, we sought to delve into the electronic and optical properties of FeS2 alloyed with ruthenium, denoted as Fe1−xRuxS2, where x varied across a range of values (x = 0.3966, 0.1586, 0.0496, 0.0347, 0.0106, and 0.00). Our theoretical analysis employed the Linear Muffin-Tin Orbital technique within the Atomic-Sphere approximation (LMTO-ASA) framework, focusing on the density of states. In parallel, our experimental samples were fabricated via a cost-effective and straightforward method involving the sulfuration of amorphous iron oxide thin films, which were deposited through spray pyrolysis of an aqueous solution containing FeCl3.6H2O onto heated glass substrates at 400 °C. This comprehensive investigation sheds light on the influence of alloying on the atomic structure and the optical characteristics of RuxFe1−xS2 samples. Utilizing X-ray diffraction (XRD) and optical characterizations, we observed a notable widening of the band gap of FeS2, ranging from 0.90508 to 1.38 eV, when approximately 1.06% of the Fe atoms were replaced with ruthenium atoms (x = 0.0106 concentration of Ru). This finding holds significant implications for the potential applications of our samples in photovoltaic technologies

Impact of Iron Pyrite Nanoparticles Sizes in Photovoltaic Performance

With rising energy demand and depleted traditional fuels, solar cells offer a sustainable and clean option. In recent years, and due to its acceptable band gap, high absorption coefficient, and inexpensive cost, iron pyrite (FeS2) is a popular material for solar cells. Earth abundance and nontoxicity further boost its photovoltaic possibilities. The current study examined the influence of sulfurization at 350–400 °C on iron pyrite layers fabricated using spray pyrolysis. The morphology and size from TEM confirmed the XRD results of synthesizing a pyrite FeS2 with an average particle size of 10–23 nm at 350–400 °C, respectively. The direct band gap calculated by DFT as a function of temperature was found to be consistent with the experimental findings, 0.87 eV (0.87) and 0.90 eV (0.95) at 350 °C and 400 °C, respectively. We found high-performing photovoltaic cells on ITO/ZnO/FeS2/ MoO3/Au/Ag, obtained with an excellent quality of nanoparticles and nanostructures of FeS2 pyrite, which improved with the method of preparation and growth parameters

The study of the electronic structure of RuS2

In this study, through theoretical and experimental analyses, we demonstrated that unlike most semiconductors, RuS2 has different indirect bandgaps, which makes it a distinct energy conversion and storage device. In our experimental work, we used the chemical vapor transport and solvent evaporation methods. We obtained RuS2 at a low temperature of 800°C with different stoichiometric shifts of sulfur, such as RuS2.00,RuS1.96, andRuS1.90. Moreover, we studied the correlation between the band structure of RuS2 calculated using the linear muffin-tin orbitals-atomic sphere approximation (LMTO-ASA) method and the growth parameters for each sample. We obtained some noteworthy values of indirect bandgap, such as, 1.84,1.72,1.42,and1.25eV,and direct transition, such as, 2.04,1.93,1.77,and1.49eV. The bandgap values obtained by LMTO-ASA are.1.80727,1.69614,1.46743,and1.23522eV.We obtained indirect bandgaps and a direct transition at the gamma point; their values are 2.04,1.94,1.77, and 1.49eV. We found that RuS2 has valence and conduction bands. The gap energy evaluated by LMTO-ASA was close to the value of that obtained through experimental measurements. We showed that band energy is insensitive to the lattice constant, a. Bandgaps depend on the method of preparation because they change with the temperature and structure (ν). Similar results were obtained for the effective mass. We found two phonons at X and M points, as well as the probability of the existence of two indirect transitions to the bandgap. To the best of our knowledge, this is the first study to confirm that the position of sulfur and S–S distance significantly affect the bandgap

Crystal Growth of RuS2 Using a Chemical Vapor Transport Technique and Its Properties

In this work, we study the effect of increasing temperature on the structure parameters (lattice, sulfur–sulfur distance, and ruthenium–sulfur distance) and the energy gap of RuS2. However, it was very challenging to obtain a sample of RuS2 due to many factors, some of which are discussed in the introduction. To prepare the crystal growth of RuS2, we have used the chemical vapor transport technique. The crystals obtained show a pyrite structure, of which we studied its crystallographic structure, including the structure of crystals in surface (100). The sample was then characterized by X-ray diffraction and by microprobe analysis. We determine the relationship between the energy gap and the sulfur–sulfur distance. We analyzed the S-S bond compared with the S2 molecule

An Insight of the Theoretical Physics of Ru-Alloyed Iron Pyrite Studied for Energy Generation

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 ~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 Th6 Pa3 saves electronic structure of iron pyrite when alloyed with ruthenium

An Insight of the Theoretical Physics of Ru-Alloyed Iron Pyrite Studied for Energy Generation

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 ~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 Th6 Pa3 saves electronic structure of iron pyrite when alloyed with ruthenium