Browsing by Author "Jasil, T.K."

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Enhancement of Functionalized 1T-NbS2 Monolayer Properties for the Superior Anode of Na-Ion Batteries
(Institute of Electrical and Electronics Engineers Inc., 2025) Jasil, T.K.; Yadav, A.K.; Maurya, G.K.; Garg, V.; Pandey, S.K.
One of the most important factors influencing the performance of Na-ion batteries (NIBs) is the anode’s quality. Currently, NIB anodes have numerous disadvantages, including low capacity, rapid volume change, temperature variable conductivity and poor thermal/chemical stability. In this work, the electronic and transport properties of undoped, doped and defective 1T-NbS2 monolayers were investigated using density functional theory calculations. The maximum quantum capacitance of 1T-NbS2 with S-vacancy (VS-NbS2) changes from 20.49 to 16.92 ?F/cm2 across temperature ranges of 200 K to 1000 K, indicating its suitability as anode with temperature-stable capacity. The 1T-NbS2 monolayers exhibit high electrical conductivity with less than 6% fluctuation across a temperature range of 200 K to 1000 K, indicating thermally stable conductance. The 1T-NbS2 layered structure has substantially larger interlayer spacing of 0.615 nm than the size of Na ion (0.095 nm), as well as a relatively tiny variation (0.05 eV for VS-NbS2) in cohesive energies between sodiated and de-sodiated phases, making it a good choice for anodes. For VS-NbS2, the seebeck coefficient ranges from -5 to -40 ?V/K, which is often obtained by the most commonly used Na-metal anode, demonstrating its appropriateness as anode. According to our findings, 1T-NbS2 is a great option for thermally stable NIB electrode applications. © 2002-2012 IEEE.
Study of Electronic and Optical Properties of Bulk and Monolayer Vanadium Di-Sulfide for Energy Storage Devices
(Institute of Electrical and Electronics Engineers Inc., 2023) Yadav, A.K.; Jasil, T.K.; Pandey, S.K.
In this study, the WIEN2k code implementation of the density functional theory (DFT) approach was used to examine the structural, electronic, and optical characteristics of bulk and monolayer VS2 material. For both bulk and monolayer VS2 material, we calculated the various properties including density of states, band-structure, and dielectric functions using the generalised gradient approximation (GGA). This method gives better results for the structural parameters and shows that monolayer VS2 is more favorable for energy storage devices. Additionally, we report the growth of the bulk and monolayer VS2 crystals using a chemical vapor deposition system. It was also found the crystal growth of monolayer VS2 started at the growth temperature of 690 Â°C. Bulk VS2 crystal growth also performed in this study. Raman spectroscopy shows a peak intensity started at 385 cm-1 for monolayer VS2 growth crystal at 690 Â°C. These observations show monolayer VS2 material is more suitable for energy storage devices. Â© 2023 IEEE.
Theoretical Investigation of BC3Monolayer for the Electrode of Na-ion Batteries
(Institute of Electrical and Electronics Engineers Inc., 2024) Vudumula, K.; Jasil, T.K.; Yadav, A.K.; Singh, R.; Vinturaj, V.P.; Pandey, S.K.
Recently, the Boron Carbide (BC3) material has gained more attention as the electrode of Li/Na ion batteries due to its ability to store lithium or sodium metal without ion clustering and phase separation. In this work, using the Quantum ESPRESSO tool, density functional theory (DFT) calculations were carried out to perform the structural and electrical properties of the BC3 monolayer material. The lattice parameters were optimized to achieve the minimum energy structure for further calculation of band structure, the density of states and dielectric constants in the pristine and Na-adsorbed on the 2 âˆ— 2 âˆ— 1 BC3 monolayer. The obtained minimum energy value is -330.302 Ry for the pristine BC3 monolayer, where as for Na- adsorbed BC3 the obtained minimum energy is -417.485. Additionally, the pristine and Na-adsorbed BC3 reveal semiconducting nature (indirect band gap 0.43 eV) and metallic nature respectively. Our study demonstrates that the BC3 monolayer has prominent potential for its application as the electrode of Na-ion batteries. Â© 2024 IEEE.
Theoretical investigation of electronic and optical properties of doped and defective MoSe2 monolayers
(Springer, 2023) Vinturaj, V.P.; Yadav, A.K.; Jasil, T.K.; Kiran, G.; Singh, R.; Singh, A.K.; Garg, V.; Pandey, S.K.
In this work, we have investigated the various electronic and optical properties of undoped molybdenum diselenide (MoSe2) monolayer, such as band structure, density of states, electron density, dielectric function, refractive index, extinction coefficient, reflectivity and energy loss function using density functional theory. Additionally, substitutional doping using niobium (Nb) and manganese (Mn) atoms and introducing defects in undoped MoSe2 lattice were investigated to know the detailed effect of the same on its properties. It is found that the undoped MoSe2 monolayer demonstrates a direct energy bandgap of ~1.44 eV, which reduces after Mn, Nb doping and after introducing Mo, Se vacancy. The energy bandgap attains a very small value 0.2 eV after introducing Se vacancy defect in MoSe2 lattice. The extinction coefficient of MoSe2 monolayer demonstrates a significant increase from 1.79 to 2.66 a.u. after introducing the Mo vacancy in the undoped lattice. The variation of semiconductor to nearly semi-metallic character of MoSe2 by introducing defects makes it very suitable for the application in high-performance solar cells, photo-electrochemical cells, sensors and biosensor applications. © 2023, Indian Academy of Sciences.