arXiv subjects

S. Gurung

Publications and source records attributed to S. Gurung.

4 recordsLinked to original sources

arXiv2025

Interfacial effect on the optoelectronic and piezoelectric properties of Ge-Sn terminated Halide Perovskite heterostructure from first-principles study

Since the very early stages of research on sustainable technologies, green energy conversion has always been a prime focus. With the discoveries of countless functional materials in recent years, significant progress has been made to meet the global energy demand for sustainable development. Among them, halide perovskites have emerged as one of the most promising and reliable materials. In this work, we have investigated the lead-free halide perovskites, vis CsGeCl3 and RbSnBr3, within a framework of density functional theory (DFT) to explore their potential applicability in harvesting clean and renewable energy. This study gives a comprehensive analysis of the bulk, surface (001), and Ge-Sn-terminated interfaces within GGA and mGGA functionals. Interestingly, the inherent asymmetric arrangements of the systems exhibit remarkable optoelectronic and piezoelectric properties. The piezoelectric performance of each surface cut has been validated through the electromechanical coupling calculation.

cond-mat.mtrl-sci↗

arXiv2025

Group-I lead oxide X$_2$PbO$_3$ (X=Li, Na, K, Rb, and Cs) glass-like materials for energy applications: A hybrid-DFT study

Pb-based compounds have garnered considerable theoretical and experimental attention due to their promising potential in energy-related applications. In this study, we explore the glass-like alkali metal lead oxides X$_2$PbO$_3$ (X=Li, Na, K, Rb, Cs) and assess their suitability for piezoelectric and thermoelectric applications. First-principles calculations were performed using hybrid density functional theory (DFT), incorporating B3LYP, HSE06, and PBE0 functionals. Among these, PBE0 is identified as the most accurate, yielding lattice parameters in close agreement with experimental data. Structural stability was confirmed through evaluation of thermal, mechanical, and formation energies. For the non-centrosymmetric orthorhombic phase Cmc2$_1$-X$_2$PbO$_3$ (X=K, Rb, Cs), piezoelectric constants were computed via both the numerical Berry phase (BP) method and the analytical Coupled Perturbed Hartree-Fock/Kohn-Sham (CPHF/KS) formalism. Notably, Cs$_2$PbO$_3$ exhibited a piezoelectric coefficient of e$_{33}$ = 0.60 C m$^{-2}$ (CPHF/KS), while K$_2$PbO$_3$ showed e$_{32}$ = -0.51 C m$^{-2}$ (BP). Thermoelectric properties were investigated using the semiclassical Boltzmann transport theory within the rigid band approximation. The calculated thermoelectric performance reveals promising figures of merit (ZT), ranging from 0.3 to 0.63, suggesting these materials are applicable as future thermoelectric materials.

cond-mat.mtrl-sci↗

arXiv2025

The study of electronic, structural, mechanical, and piezoelectric properties of bulk NbOX2 (X = Cl, Br, and I) using density functional theory

In this work, we have performed a comprehensive study of dielectric materials NbOX2 (X=Cl, Br, and I) within the framework of density functional theory, incorporating both conventional and hybrid functionals.Our studies focus on the structure, electronic, elastic, and piezoelectric properties. Piezoelectricity is an innovative avenue to extract energy by manipulating the material's structures via mechanical stress. The use of non-lead-based material for piezoelectricity added an advantage of a greener approach. Among the investigated materials, bulk NbOI2 exhibits the highest piezoelectric response of 6.32 C/m$^2$, which is around 31% higher than NbOCl2, NbOBr2 and even lead zirconate titanate.

cond-mat.mtrl-sci↗

arXiv2024

Recent progress on the solid-state materials for photocatalysis

Hydrogen is considered an alternative source of energy to fossil fuels for the fulfilment of current energy demands. Photocatalysis initiates the hydrogen evolution reaction which is believed to be the greenest approach to produce hydrogen through clean, safe, and environmentally friendly methods. In this Review, we focus mainly on the comprehensive analysis of the 2D and 3D bulk materials on the basis of their superior photocatalytic activities. However, several literatures have reported the superiority of 2D material over the bulk counterpart in terms of photocatalytic performance owing to their ultrathin layered structures, offer a higher surface-to-volume ratio, flexibility, large active sites for incoming H2O molecules, etc. We have thoroughly analysed the drawbacks of various hydrogen production methods focusing on the photocatalysis mechanism and the processes of evolution of hydrogen. In addition to this, a short overview of the various solid-state materials for photocatalysis that have been developed so far and their mechanisms are discussed. Lastly, we have discussed the recent developments in 2D materials and their composites as promising photocatalysts.

cond-mat.mtrl-sci↗