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A Review of the Theoretical Results Associated with the Intermediate Bandgap Solar Cell Materials
Published in Amit Soni, Dharmendra Tripathi, Jagrati Sahariya, Kamal Nayan Sharma, Energy Conversion and Green Energy Storage, 2023
Aditi Gaur, Karina Khan, Amit Soni, Jagrati Sahariya, Alpa Dashora
Antimony sulfide (Sb2S3) thin films are quite interesting as they play the role of absorbing layer for solar cell applications. The first principle approach has been adopted to study the electronic and optical properties of Sb2S3 thin films. The DFT approach has been implemented in the WIEN2k package in the form of a highly accurate full-potential linearized augmented-plane-wave method. The optical properties analysis of the Sb2S3 thin films has shown better optical-based absorption lying in the spectrum of visible light and UV wavelengths. It is predicted to be used as an imbibing layer in solar cells and optoelectronic-based devices [40]. Cu3N film’s comprehensive study using first principles through the theory of density functional based on electronic, structural and optical properties was performed. From the first principles along with Hubbard term (LDA + U), the bandgap is calculated and it turns out to be indirect in nature with a value of about 1.4 eV for the Cu3N film. This value lies nearer to the calculated experimental value, i.e., 1.44 eV which is achieved using UV–vis absorption spectrum [41].
Determination of the mean inner potential in III-V semiconductors by electron holography
Published in A. G. Cullis, P. A. Midgley, Microscopy of Semiconducting Materials 2003, 2018
P Kruse, A Rosenauer, D Gerthsen
ABSTRACT: The mean inner potential of GaAs (14.2V), InAs (14.5V), GaP (14.5V) and InP (14.5V) has been measured by transmission electron holography in combination with convergent beam electron diffraction and high-resolution transmission electron microscopy. Dynamical effects are taken into account by Bloch-wave calculations. The results are compared to density functional theory calculations obtained with the Wien2k Software package.
Insight into the structural, electronic, optical, and elastic properties of niobium carbide
Published in Phase Transitions, 2023
Mohammed S. Abu-Jafar, Raed Jaradat, Mahmoud Farout, Areej Shawahneh, Ahmad A. Mousa, Khalid Ilaiwi, Rabah Khenata, Said M. Azar
Research on the monometallic carbide NbC has been performed using the density functional theory (DFT), which was employed in the WIEN2k [16] software package. The Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA) has been used to deal with the exchange correlation potential [17]. The full potential approximation partitions the atomic space into two, differing main parts: the non-overlapping spheres (muffin-tin spheres) with radius RMT and the interstitial part. The estimated RMT values are 2.21 and 1.68 a.u for Nb and C atoms, respectively. In the interstitial part, the basis sets were expanded in plane waves, while spherical harmonics multiplied by one particle radial functions and their energy derivatives were used in the non-overlapping spheres. In the two regions, to get adequate and suitable energy convergence, the system set functions were expanded up to RMT × Kmax = 7, where Kmax is the maximum k-vector value magnitude used in the plane wave functions. In the atomic sphere’s region, the used charge density expanded in the Fourier expansion up to Gmax = 12 with a cut-off lmax = 8. To reach self-consistency, the unit cell energy per unit cell was repeated until the predicted energy value converged to less than 10−5 Ry. The appropriate energy used to separate the core state from the valence is −6.0 Ry. We used 3500 and 2000 k-points for the hexagonal and cubic structures in the full Brillouin zone (FBZ), respectively. They reduced in the irreducible Brillouin zones (IBZ) to 56 and 46 special k-points [18].
Magnetocaloric and thermoelectric properties of the perovskite LaMnO3 material: A DFT study and Monte Carlo technique
Published in Phase Transitions, 2021
N. Tahiri, S. Dahbi, I. Dani, O. El Bounagui, H. Ez-Zahraouy
The calculations are performed based on density functional theory (DFT) as implemented in the Wien2k code by using the full potential Linearized augmented plane wave method (FP-LAPW) [20,21]. The Generalized Gradient Approximation with the modified Becke–Johnson (GGA + mBJ) [22,23] is used for exchange and correlation. The electronic structure and magnetic properties of the perovskite LaMnO3 material are investigated using these approximations. The present material crystallizes in the cubic structure with space group Pm3 m, see Figure 1. The value of RMT × Kmax is equal to 7, where RMT is the small atomic radius in the unit cell and Kmax is the size of the largest vector in the plane wave expansion. The achieved convergence value is fixed at 10−4. The Monkhorst–Pack k-mesh in the Brillouin zone used 6 × 6 × 6 for the lattice parameters optimized and the calculations of electronic structure and magnetic properties. All parameters of the perovskite LaMnO3 material are calculated using first-principles approximations at . These parameters are the magnetic moment, the exchange coupling constants between Mn atoms and the crystal field , take the following values: , and , respectively.
Structural stability, electronic and mechanical properties of transition metal nitrides TMN compounds (TM=Zn, Mn and Tc)
Published in Phase Transitions, 2021
Pushplata Shukla, Sadhna Singh
Electronic structure calculations were performed using the full-potential linearized augmented plane wave method, as implemented in WIEN2k package, which is based on the density functional theory [34]. We have used the generalized gradient approximation (GGA) approach for exchange and correlation effects [35]. The calculations were performed using a dense mesh of 1000K-points and the tetrahedral method [36] was used for the Brillouin zone integration. The energy convergence is achieved by expanding the basis function up to RMT*Kmax = 7, where RMT is the smallest atomic radius in the unit cell and Kmax refers to the magnitudes of the largest k vector in the plane wave expansion. The maximum value for partial wave inside the atomic sphere is lmax = 10, while the charge density is Fourier expanded up to Gmax = 12 (a.u.)−1. The self-consistent calculations are converged when the total energy of the system is stable within 10−4 Ry. Energy to separate core and valance state is −6.0 Ry.