scholarly journals Investigation on the electronic structure, optical, elastic, mechanical, thermodynamic and thermoelectric properties of wide band gap semiconductor double perovskite Ba2InTaO6

RSC Advances ◽  
2019 ◽  
Vol 9 (17) ◽  
pp. 9522-9532 ◽  
Author(s):  
Sajad Ahmad Dar ◽  
Ramesh Sharma ◽  
Vipul Srivastava ◽  
Umesh Kumar Sakalle

In the present paper, double perovskite Ba2InTaO6 was investigated in terms of its structural, electronic, optical, elastic, mechanical, thermodynamic and thermoelectric properties using density-functional theory (DFT).

RSC Advances ◽  
2020 ◽  
Vol 10 (27) ◽  
pp. 16179-16186 ◽  
Author(s):  
Shalika R. Bhandari ◽  
D. K. Yadav ◽  
B. P. Belbase ◽  
M. Zeeshan ◽  
B. Sadhukhan ◽  
...  

With the help of density functional theory calculations, we explored the recently synthesized double perovskite material Ca2CrOsO6 and found it to be a ferrimagnetic insulator with a band gap of ∼0.6 eV.


2021 ◽  
Author(s):  
Deepti Maikhuri ◽  
Jaiparkash Jaiparkash ◽  
Haider Abbas

Abstract We present a comprehensive first-principles study of the electronic structure of graphene sheet with periodic vacancy. We report the structural, electronic, and magnetic properties of the graphene sheet with periodic vacancy that possess 48 C & 28 H atoms. Computational analysis based on density functional theory predicts that the periodic vacancy can modulate the properties of graphene sheet. Results show that periodic vacancies lead to the manipulation of band gap & could be utilized to tailor the electronic properties of the sheet. Also, it is found that, the graphene sheet with periodic vacancy is non-magnetic in nature.


2012 ◽  
Vol 465 ◽  
pp. 33-36
Author(s):  
Zhi Dong Lin ◽  
Wen Long Song ◽  
Ju Cheng Zheng

The band structure and density of states (DOS) of Ti1-xSnxO2 solid solutions with x=0, 1/8, 1/4, 1/2 and 1 were investigated by means of the first-principle calculations based on density functional theory. The result indicated that band gap and Fermi level of TiO2-SnO2 vary continuously from those of pure TiO2 to those of Sn content increasing. In addition, the DOS moves towards low energy and the bang gap is broadened with growing value of x. The wide band gap and the low density of the states in the conduction band result in the enhancement of photoactivity in Ti1-xSnxO2.


2020 ◽  
Vol 833 ◽  
pp. 157-161
Author(s):  
Mauludi Ariesto Pamungkas ◽  
Husain ◽  
Achmad Kafi Shobirin ◽  
Tri Sugiono ◽  
Masruroh Masruroh

Germanene, which has the same structure as graphene, is an exciting novel 2D functionalized material that controls its band gap using functionalization. The effects of the Ga atom and hydrogen atoms on the structure of Ga-doped H-passivated germanene were investigated with a density functional theory (DFT) calculation. H-passivated germanene has a direct gap of 2.10 eV. Opening the band gap in the H-passivated germanene is due to transition from sp2 to sp3 orbital. Adsorption of the Ga adatom on H-site decrease the band gap to 1.38 eV. No interaction between Ga atoms and Hydrogen atoms was observed. Hence, their effects on the band structure of hydrogenated graphene were independent of each other. Our results suggest that hydrogen passivation combined with adsorption of the Ga adatoms could effectively control the band gap of germanene.


Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 709 ◽  
Author(s):  
Qing-Lu Liu ◽  
Zong-Yan Zhao ◽  
Jian-Hong Yi ◽  
Zi-Yang Zhang

As important functional materials, the electronic structure and physical properties of (GaAs)m(AlAs)n superlattices (SLs) have been extensively studied. However, due to limitations of computational methods and computational resources, it is sometimes difficult to thoroughly understand how and why the modification of their structural parameters affects their electronic structure and physical properties. In this article, a high-throughput study based on density functional theory calculations has been carried out to obtain detailed information and to further provide the underlying intrinsic mechanisms. The band gap variations of (GaAs)m(AlAs)n superlattices have been systematically investigated and summarized. They are very consistent with the available reported experimental measurements. Furthermore, the direct-to-indirect-gap transition of (GaAs)m(AlAs)n superlattices has been predicted and explained. For certain thicknesses of the GaAs well (m), the band gap value of (GaAs)m(AlAs)n SLs exponentially increases (increasing n), while for certain thicknesses of the AlAs barrier (n), the band gap value of (GaAs)m(AlAs)n SLs exponentially decreases (increasing m). In both cases, the band gap values converge to certain values. Furthermore, owing to the energy eigenvalues at different k-points showing different variation trends, (GaAs)m(AlAs)n SLs transform from a Γ-Γ direct band gap to Γ-M indirect band gap when the AlAs barrier is thick enough. The intrinsic reason for these variations is that the contributions and positions of the electronic states of the GaAs well and the AlAs barrier change under altered thickness conditions. Moreover, we have found that the binding energy can be used as a detector to estimate the band gap value in the design of (GaAs)m(AlAs)n devices. Our findings are useful for the design of novel (GaAs)m(AlAs)n superlattices-based optoelectronic devices.


2017 ◽  
Vol 16 ◽  
pp. 47-51
Author(s):  
Emmanuel Igumbor ◽  
Ezekiel Omotoso ◽  
Walter Ernst Meyer

We present results of defect formation energies and charge state thermodynamic transition levels of Mg and Te interstitials in MgTe wurzite structure. We use the generalized gradient approximation and local density approximation functionals in the framework of density functional theory for all calculations. The formation energies of the Mg and Te interstitials in MgTe for both the tetrahedral and hexagonal configurations were obtained. The Mg and Te interstitials in MgTe depending on the functional, introduced transition state levels that are either donor or acceptor within the band gap of the MgTe. The Te interstitial exhibit charge states controlled metastability, negative-U and DX centre properties. The Mg interstitial acts as deep or shallow donor and there is no evidence of acceptor levels found for the Mg interstitial.


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