Electronic and optical properties of pentagonal-B 2 C monolayer: A first-principles calculation

Khalil

et al. 2020

Mater. Res. Express

We have examined structural, electronic and optical properties of TM-GaO 3 (TM=Sc, Ti, Ag) perovskite oxides by means of first Principles study based on density functional theory (DFT). TM represents transition metal elements. To investigate structural properties, exchange correlation potential was determined by employing Full Potential Linearly Augmented Plane Wave (FP-LAPW) technique along with Perdew-Burke-Ernzerhof -GeneralizedGradient Approximation (PBE-GGA) functional. Moreover, Hubbard U eff parameter LDA+U was used to overcome limitations of PBE-GGA functional. All compounds TM-GaO 3 (TM=Sc, Ti, Ag) seem semi-conductor in nature because indirect band gap in each case has been observed with energies 1.33 eV, 0.75 eV and 1.95 eV, respectively. Partial density of states (PDOS) analyses portrayed that 3d orbitals of Sc & Ti, 4d orbital of Ag, and 2p orbital of anions contribute mainly to increase electronic conductivity of the studied compounds. Charge density contour plots depicted ionic nature of TM-cations, while, significant sharing of isolines between O and Ga atoms showed covalent character between them. These contours have also confirmed accumulation of charges around O atoms. Optical analysis revealed that the considered perovskite oxides show sharp increase in optical conductivity and absorptivity in higher energy range when energetic photons are incident upon. Remarkably, they displayed poor reflectivity. However, defect states introduced in the band gap region might be due to cations. These composites are suitable for photovoltaics and other optoelectronic applications OPEN ACCESS RECEIVED

Section: Structural and Electronic Propertiesmentioning

confidence: 99%

Investigations of structural, electronic and optical properties of TM-GaO₃ (TM = Sc, Ti, Ag) perovskite oxides for optoelectronic applications: a first principles study

Khalil

et al. 2020

Mater. Res. Express

“…In general, magnetism in materials occurs due to orientation of the magnetic domains associated with their constituent atoms. Additionally, the electronic band gap energy and density of states are reckoned to be more reasonable to comprehend the crystal structure of any solid material, 36,37 which portrays magnetic behavior of such materials, so these parameters need to be invoked. We have, therefore, presented here spin-polarized band structures, total and projected density of states (PDOSs) along high symmetry paths of the first BZ for considered tantalate perovskite oxides XTaO 3 (X = Rb, Fr).…”

Section: Magnetic and Electronic Propertiesmentioning

confidence: 99%

DFT ‐based insight into the magnetic and thermoelectric characteristics of XTaO ₃ (X = Rb, Fr) ternary perovskite oxides for optoelectronic applications

et al. 2020

Summary Nowadays, there exists an increasing trend of investigating ternary perovskite oxide materials because of their wide applications in solar cells and similar electronic and optoelectronic devices. This work describes a systematic study performed through state‐of‐the‐art ab initio density functional theory (DFT) approach associated with the magnetic, electronic, and thermoelectric behavior of XTaO3 (X = alkali metals i.e., Rb, Fr) tantalate perovskite oxides. These compounds are found to be semiconductor because both materials have shown significant values of the band gap energy, that is, indirect energy band gap of 1.12 eV (↑↓) in RbTaO3 and direct band gap of 1.08 eV (↑↓) in FrTaO3. The calculated formation energies appear to be decreasing such as −3.54 and −1.92 eV for RbTaO3 and FrTaO3, respectively. The analysis through projected density of states discloses that Fr‐6p and 2p states from anion sites have shown overall contribution in forming the highest edge of the valence band (VBM), while, Ta‐5d states have depicted chief role to form major part of the conduction band minima, thereby, contributing in electronic conductivity. The much better values of thermoelectric parameters such as power factor of (5.5062 × 1013 W.m−1.K−2.s−1) and figure of merit (0.82) demonstrate that RbTaO3 is more dominating and promising semiconducting material which would, comparatively, be deemed an appropriate candidate for application in developing efficient thermoelectric devices. Finally, on the bases of above cited facts and the already existing data on similar perovskite oxides, it can be speculated that the studied compounds seem potential candidates to understand underlying physics and for possible applications in thermoelectric and other allied devices.

“…It is well known that the electronic band structure and density of states (DOS) are important quantities to determine the crystal structure [12,13]. In order to understand bonding character clearly, the total and partial densities of states (DOS) is calculated in Figure 3.…”

Section: Electronic and Magnetic Propertiesmentioning

confidence: 99%

AB-INITIO CALCULATIONS OF STRUCTURAL, ELECTRONIC AND MAGNETIC PROPERTIES OF LiRh2Si2

Balcı¹,

Ayhan²

2018

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