Ab initio calculations of optoelectronic properties of antimony sulfide nano-thin film for solar cell applications

Antimony sulfide (Sb2S3) micro thin-film have been received great interest as an absorbing layer for solar cell technology. In this study, to explore its further potential, electronic and optical properties of Sb2S3 simulated nano-thin film are investigated by the first-principles approach. To do so, the highly accurate full-potential linearized augmented plane wave (FP-LAPW) method framed within density functional theory (DFT) as implemented in the WIEN2k package is employed. The films are simulated in the [0 0 1] direction using the supercell method with a vacuum along z-direction so that slab and periodic images can be treated independently. From our calculations, indirect band gap energy values of Sb2S3 for various slabs are found to be 0.568, 0.596 and 0.609 eV for 1, 2 and 4 slabs respectively. Moreover, optical properties comprising of real and imaginary parts of the complex dielectric function, absorption coefficient, refractive index are also investigated to understand the optical behavior of the obtained simulated Sb2S3 thin films. From the analysis of their optical properties, it is clearly seen that Sb2S3 thin films have good values for optical absorption parameters in the visible and ultraviolet wavelength range, showing the aptness of antimony sulphide thins films for versatile optoelectronic applications as a base material

First-principles calculations of antimony sulphide Sb2S3

The structural, electronic and optical properties of Sb2S3 have been investigated using full-potential linearized augmented plane wave method within density functional theory (DFT) framework, treating exchange-correlation potential with Engel-Vosko generalized gradient approximation (EV-GGA). Electronic properties calculations were performed with and without taken into account the effects of spin-orbit coupling (SOC) . From our results we found that structural properties,density of states and band structure are in good agreement with experimental results.The effects of SOC and relativistic on electronic properties were found to be negligible. However, optical properties, namely, imaginary and real parts of dielectric function, reflectivity, absorption coefficient, refractive index, extinction coefficient and energy loss function were calculated and analyized.Optical gap of 1.61 eV proves that Sb2S3 metal chalcogenides is a promising material for solar cell device

Electronic properties of palladium diselenide by density functional theory

The knowledge of the structural and electronic properties of a material is important in various applications such as optoelectronics and thermoelectric devices. In this study, we are using full potential linearized augmented plane wave method framed within density functional theory provided by WIEN2k to optimize the structure of PdSe2 in orthorhombic (Pbca) phase and calculate its electronic properties. With the implementation of local density approximation (LDA), Perdew-Burke-Ernzerhof parameterization of generalized gradient approximation (PBE-GGA), Wu-Cohen parameterization of GGA (WC-GGA), and PBE correction for solid GGA (PBEsol-GGA), the computed results of lattice constants are found to be within 5% error with the experiment data. Also, our calculated indirect band gap energy was found to be ~0.24 eV by LDA along with modified Becke-Johnson potential functional (mBJ) with experimental lattice constants and ~0.52 eV by using PBE-GGA with optimized lattice constants. However, the effect of spin-orbit coupling is not found too much on the band gap energy. By analyzing the partial density of states, we identify that d-orbital of Pd is demonstrating a slightly more significant contribution to both the valence and conduction band near to Fermi level which is also in agreement with the previous first principles study

First-principles study of electronic and optical properties of antimony sulphide thin film

First-principles quantum mechanical computational methods are significant tools to understand the details of crystal structures which might be difficult through experimentation. In this paper, we have presented the electronic and optical properties of the thin film structure of Sb2S3 in (001) orientation. Density functional theory based approaches are employed to determine the band structure, density of states (DOS), dielectric function and other optical parameters. Here, the investigations have been performed by full-potential linearized augmented plane-wave method (FP-LAPW) within the WIEN2k computational code. The band structure computations are done at the level of LDA-PW, PBE-GGA, PBE-GGA with SOC and PBE-GGA with mBJ potential, whereas for optical properties only PBE-GGA with mBJ potential was applied. Our calculations revealed that similar to optical properties, Sb2S3 (001) oriented thin film had shown a reduction in the band gap energy than its counterpart bulk structure. This reduction, in the electronic and optical parameters, might be better understood in the course of quantum confinement effect for improving its performance for optoelectronics applications

Ab initio calculations of antimony sulphide nanowire

We have performed first-principles calculations on orthorhombic antimony sulphide (Sb2S3) nanowire using full-potential linearized augmented plane wave (FP-LAPW) method based on the density-functional theory (DFT) as implemented in WIEN2k package to investigate the electronic and optical properties. Engel–Vosko generalized gradient approximation (EV-GGA) is used as exchange-correlation functional. The nanowire is simulated in the [001] direction with vacuum in two directions using supercell method. The results are compared with Sb2S3 bulk results obtained in our previous study. We have found that the electronic and optical properties significantly change in Sb2S3 nanowire. The density of state (DOS) for Sb2S3 nanowire calculated is higher than bulk Sb2S3 and from the electronic band structure, the indirect band gap is about 0.12 eV where this value is much lower than Sb2S3 bulk. However, this value is much lower than experimental value. The optical properties including absorption coefficient, reflectivity, refractive index and energy loss function are derived from the calculated complex dielectric for photon energy up to 20 eV to understand the optical behavior of Sb2S3 in one-dimensional (1-D) nanostructure. From analysis, the optical response of Sb2S3 nanowire demonstrate quite interesting optical behavior for one-dimension (1-D) nanostructure. The absorption coefficient for Sb2S3 nanowire is considerably higher in visible light range than Sb2S3 bulk

First-principles calculations of the stibnite at the level of modified Becke-Johnson exchange potential

The demand for cheaper, nontoxic and earth-abundant materials as absorbing layer for solar cell is immensely needed to replace scarce, toxic and expensive one. In this regard, chalcogenide materials have considerably attracted the attention of a lot of researchers because of showing a great potential for different applications. Stibnite (Sb2S3), a chalcogenide binary material is considerably investigated for exploiting its potential for different energy technologies being a less toxic, abundantly available, stable and efficient, which are the fundamentals for sustainability as well as to realize the dream of green energy. In this study, theoretical calculations of the structural, electronic and optical properties of stibnite (Sb2S3) crystal structure are presented using the full potential (FP) linearized augmented plane wave (LAPW) framed within density functional theory (DFT). To incorporate the exchange-correlation part in the total energy functional, besides the local density approximation (LDA), Wu-Cohen parameterized generalized gradient approximation (WC-GGA), Perdew–Burke–Ernzerhof parameterized generalized gradient approximation (PBE-GGA), and Perdew–Burke–Ernzerhof generalized gradient approximation for solids and surfaces (PBEsol-GGA) are used for the calculations of the structural parameters, where the Trans-Blaha approach of the modified Becke–Johnson (TB-mBJ) potential is used to get more reliable results for the fundamental band gap energy value. These calculations are performed by involving spin-orbit coupling (SOC) contribution. Additionally, optical properties, such as imaginary and real parts of the dielectric function, optical conductivity, absorption coefficient, refractive index, reflectivity, and electron energy loss function are analyzed. Our first-principles calculations show that Wu-Cohen GGA (WC-GGA) reproduces results for lattice parameters comparable to the experimental measurements. The obtained results of the band gap energy and optical properties with TB-mBJ potential are also closer to the experimental data and, endorse its potentiality for the photovoltaics applications

First-principles calculations of structural, electronic, and optical properties for Ni-doped Sb2S3

Antimony sulphide (Sb2S3) is a potential candidate for alternative material in solar cell application. The structural, electronic, and optical properties of Ni doped Sb2S3 were calculated using full potential linear augmented plane wave (FP-LAPW) based on popular density-functional theory (DFT). The equilibrium lattice parameters have been calculated using Perdew–Burke–Ernzerhof (PBE) generalized gradient approximation (PBE-GGA). The band structure and density of state for Ni-doped Sb2S3 have been determined using Tran Blaha modified Becke-Johnson (TB-mBJ) potential. Our results indicate that Ni doped Sb2S3 has lower band gap energy compare to pure-Sb2S3. The optical properties of Ni-doped Sb2S3 such as absorption coefficient, reflectivity, refractive index, energy-loss function and extinction coefficient are presented. The results demonstrate that Ni-doped Sb2S3 has higher optical absorption coefficient in the visible region than pure-Sb2S3 which is good for optoelectronic applications

First-principles investigation of structural, elastic, electronic and thermodynamic properties of strongly correlated ternary system: The DFT plus U approach

The elastic, thermodynamic and electronic properties of rhombohedra SiFe2O4 spinel-type are investigated using generalized gradient approximation (GGA) and local density approximation (LDA) approach. The results obtained confirmed the failure of bare DFT to produce the fundamental bandgap of strongly correlated systems. By incorporating the Hubbard correction term (U) on Fe 3d electron, the calculated bandgap using GGA + U was found to be 3.86 eV and this value is comparable with experimental data. The Pugh's ratio and Cauchy pressure values demonstrate the ductility nature of SiFe2O4 spinel. The temperature variation with thermodynamic properties descript the stability of SiFe2O4 spinel. The heat capacity at constant volume increases sharply with temperature and tends to the Dulong-Petit limit at high temperature. The reported value of the bandgap lies within near-ultraviolet (UV) wavelength, revealing that SiFe(2)O(4)spinel-type material may be useful for the photo electrochemical cell of water splitting, flat-panel displays and other optoelectronic applications

G0W0 plus BSE calculations of quasiparticle band structure and optical properties of nitrogen-doped antimony trisulfide for near infrared optoelectronic and solar cells application authors

Theoretical calculations of structural, electronic, excitonic and optical properties of N-doped Sb2S3 are studied using highly accurate first-principles approach within many-body perturbation theory (MBPT) formalism. The calculated structural parameters of undoped Sb2S3 within Wu-Cohen’s generalized gradient approximation (WC-GGA) are reasonably close to those obtained in experimental measurement. Many-body perturbation theory (MBPT) based on the G0W0 approximation is used for the quasiparticle (QP) band structure. The bandgap value of 1.70 eV for the undoped Sb2S3 crystal within G0W0 approximation is consistent with the experimental value of 1.70–1.80 eV. When one atom of N is introduced into Sb2S3 at Sb site, the doping effects modified the band gap from 1.70 to 1.17 eV. Also, by introducing one atom of N to S site, the band gap value reduced to 0.96 eV. Our findings confirmed that non-metal doping narrow the energy gap of semiconductor materials. The optical properties of pure and N-doped Sb2S3 are computed using G0W0 plus Bethe-Salpeter Equation (BSE) which include both electron-electron (e-e) and electron-hole (e-h) interactions. The optical gap for Sb16S24, Sb15N1S24 and Sb16S23N1 were found to be 1.54, 0.97 and 0.82 eV, respectively. The narrowing effects and strong optical absorption of N-doped Sb2S3 suggest that the investigated material is suitable for solar cells and near infrared optoelectronic applications

Structural and electronic properties of orthorhombic phase Bi₂Se₃ based on first-principles study / Muhammad Zamir Mohyedin ... [et al.]

Bi₂Se₃ is one of the promising materials in thermoelectric devices and is environmentally friendly due to its efficiency to perform in room temperature. Structural and electronic properties of Bi2Se3 were investigated based on the first-principles calculation of density functional theory (DFT) using CASTEP computer code. The calculation is conducted within the exchange-correlation of local density approximation (LDA) and generalised gradient approximation within the revision of Perdew-Burke-Ernzerhof (GGA-PBE) functional. A comparative study is carried out between the electronic properties of LDA and GGA-PBE. Lattice parameter and band gap are consistent with the other reports. Calculation from LDA is more accurate and has a better agreement than GGA-PBE in describing the lattice parameter of Bi2Se3. Band gap and density of states of LDA show higher electrical conductivity than GGA-PBE. Both LDA and GGA-PBE have same degree of thermal conductivity due to the occurrence of indirect band gap at same range of wave vector