arXiv subjects

Lalhriat Zuala

Publications and source records attributed to Lalhriat Zuala.

7 recordsLinked to original sources

arXiv2026

A DFT and Machine Learning-Assisted Study on the Lattice Thermal Conductivity of LiCdSb for Thermoelectric Applications

By using first-principles density functional theory (DFT) and the Boltzmann transport equation, we have calculated the corresponding electronic and thermoelectric properties of LiCdSb. For calculating electron transport properties, accurate band-structure estimation is crucial. Hence, for the precise band gap calculation, we have implemented a hybrid functional HSE06, which is widely known for its high accuracy. To evaluate the thermoelectric performance of a material, the calculation of lattice thermal conductivity (Kl) is a key parameter. However, from a theoretical perspective, the calculation of lattice thermal conductivity is very complex and demands huge computational resources. Therefore, in this work, we have opted for an alternative method of machine-learning interatomic potentials (MLIPs) for the calculation of Kl. Our result of Kl=0.24 Wm^-1K^-1 at room temperature is in qualitative agreement with the available theoretical and experimental data. The figure of merit (ZT) with Kl estimated from Slack+TDEC ZT is 0.18 at 300 K, and machine learning (ML) models ZT is 0.17 at 300K, combining with HSE06-based electronic transport properties agreed well with the available experimentally reported value of ZT is 0.10 at 300K. However, we report the ZT value well above the benchmark value of 1 beyond 600K. The ZT value exceeding 1 at higher temperatures makes LiCdSb a promising material for high-temperature energy conversion.

cond-mat.mtrl-sci↗

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

A comprehensive first principles investigation of A$_2$BH$_6$ type (A= Li,Na, and K; B= Al, and Si) double perovskite hydrides for high capacity hydrogen storage

Recent breakthroughs in vacancy-ordered double perovskite hydride materials have underscored their significant potential for integration into next-generation high-capacity hydrogen energy storage systems. We perform extensive first principles calculations leveraging both the GGA and hybrid-HSE06 functionals to systematically explore the intrinsic properties of A$_2$BH$_6$ complex hydrides. Thermodynamic stability for each hydride is demonstrated and confirmed by negative formation energies, determined by both the GGA and HSE06 formalisms. Additionally, mechanical stability is validated through compliance with Born's stability criteria. Electronic properties analysis reveals a semiconducting behavior in Si based hydrides (A2SiH6 ), whereas Al based (A$_2$AlH$_6$) display metallic nature, regardless of the A site atoms and functionals adopted. For the semiconducting hydrides, we have observed higher optical absorption peak greater than 106 (1/cm) in the UV regime indicating potential application in UV-optoelectronic devices. Furthermore, all studied compounds adhere to Debye's low-temperature specific heat behavior and converge to the classical Dulong-Petit limit at elevated temperatures, in accordance with fundamental thermodynamic principles. For hydrogen storage applications, both Al- and Si-based hydrides. meet key benchmarks set by the U.S. Department of Energy (DOE), achieving gravimetric hydrogen capacities (C$_{wt}$) exceeding 5.5 percent when A = Li or Na, and exhibiting volumetric hydrogen densities greater than 40 g.H2/L. Among all studied hydrides, Li$_2$AlH$_6$ and Li$_2$SiH$_6$ emerge as the two most promising candidates due to their outstanding Cwt greater than 12.0 percent , elevated density greater than 140 g.H$_2$/L, and favorable hydrogen desorption temperature ranges TD = 450 to 650 K.

cond-mat.mtrl-sci↗

arXiv2025

Exploring the functional properties of diamond-like quaternary compound Li$_2$ZnGeS$_4$ for potential energy applications: A theoretical approach

It is anticipated that wide-bandgap semiconductors (WBGSs) would be useful materials for energy production and storage. A well-synthesized, yet, scarcely explored diamond-like quaternary semiconductor-Li$_2$ZnGeS$_4$ has been considered for this work. Herein, we have employed two well-known functionals GGA and mGGA within a frame-work of density functional theory (DFT). We have explored the electronic, optical, mechanical, and piezo-electromechanical properties. Our results are in qualitative agreement with some of the previously reported data. The structural stabilities have been confirmed using the Born stability criteria and Molecular-dynamic (MD) simulations. Based on our findings, we claim that Li$_2$ZnGeS$_4$ is the most probable candidate for optoelectronics and piezoelectric applications.

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↗

arXiv2024

A comprehensive study of electronic and piezoelectric properties of Li-based Tin-halide perovskites from GGA and Meta-GGA

Wide bandgap semiconductors (WBGs) are predicted to be the potential materials for energy generation and storing. In this work, we used density functional theory (DFT) that incorporates generalized gradient approximation (GGA) and meta-generalized gradient approximation (mGGA) methods to explore the various properties of the LiSnCl3 and LiSnBr3 perovskites. The structural stabilities, charge transfer, electronic, optical, mechanical, and piezoelectric properties are studied. Herein, we report that these rarely studied materials are eco-friendly and look promising for optoelectronics and piezoelectric applications.

cond-mat.mtrl-sci↗

arXiv2024

Modulation of electronic and piezoelectric properties of lead-free halide perovskites LiSnX$_3$ (X = Cl, Br, and I) under applied pressure

Pb-based perovskites are considered to be the most efficient materials for energy harvest. However, real-time application is limited because of their toxicity. As a result, lead-free perovskites that offer similar advantages are potential alternatives. Here, we have chosen LiSnX$_3$ (X = Cl, Br, and I) for further calculation and explore its possibilities for harvesting clean and green energy. Our objective is to examine strategies for optimizing the parameters that control the energy-harvesting capabilities, particularly the interplay between structural variations and electrical properties. The density functional theory (DFT) has been employed for the theoretical simulation. Within the DFT framework, we have studied the effect of applied pressure (0 to 20 GPa) and elemental substitution on their physical properties. We hereby report the variation of lattice parameters, elastic constants, band gaps, and piezoelectric constants. MD simulation with time steps of up to 5 ps was performed to verify structural stability at room temperature. We report the semi-conducting characteristic of LiSnX$_3$ and the high piezoelectric response up to 20.7 Cm2. The presence of high piezoelectric coefficients suggests that manipulation of the structure of LiSnX$_3$ may provide an alternative way to harvest energy through electromechanical processes.

cond-mat.mtrl-sci↗