arXiv subjects

Priya Johari

Publications and source records attributed to Priya Johari.

16 recordsLinked to original sources

arXiv2026

Rare-earth chalcogenide perovskites: A promising class of materials for optoelectronic applications

Rare-earth chalcogenide perovskites have attracted significant attention for optoelectronic applications due to their nontoxic composition, robust phase stability, and excellent optoelectronic properties. However, their excitonic and polaronic properties remain largely unexplored due to the high computational cost of accurate theoretical treatments. In this work, we present a comprehensive first-principles investigation of excitonic dynamics and polaronic effects in a series of III-III rare-earth chalcogenide perovskites ABX$_{3}$ (A = Y, La; B = Sc, Y; X = S, Se), along with their structural stability and optoelectronic properties, using state-of-the-art density functional theory in conjunction with many-body perturbation theory within the G$_{0}$W$_{0}$ and Bethe-Salpeter equation (BSE) frameworks. All investigated compounds satisfy the dynamical and mechanical stability criteria. They exhibit quasiparticle band gaps in the range of 2.75$-$4.47 eV, and the BSE calculations reveal strong optical absorption spanning the visible to ultraviolet regions. The computed excitonic properties indicate intermediate-to-large exciton binding energies (0.148$-$0.517 eV), moderately localized excitons, and strong electron-hole wavefunction overlap, indicative of favorable radiative recombination characteristics and enhanced light-matter interaction. Furthermore, analysis based on the Fr\"ohlich model demonstrates intermediate-to-strong carrier-phonon coupling, with electron-phonon interactions generally stronger than hole-phonon interactions. Overall, rare-earth chalcogenide perovskites ABX$_{3}$ exhibit a compelling combination of structural stability, tunable optoelectronic properties, pronounced excitonic effects, and favorable polaronic transport, positioning them as promising lead-free materials for next-generation optoelectronic devices, including light-emitting devices and photodetectors.

cond-mat.mtrl-sci↗

arXiv2026

Lead-free antiperovskite derivatives Ba$_3$MA$_3$ (M = P, As, Sb, Bi; A = Cl, Br, I): Next-gen materials for optoelectronics

Antiperovskite derivatives have recently emerged as promising lead-free alternatives to halide perovskites for optoelectronic applications. Here, using a comprehensive first-principles calculations including density functional perturbation theory and many-body perturbation theory (involving GW and Bethe-Salpeter equation (BSE)), we investigate the stability, excitonic, polaronic, and optoelectronic properties of cubic Ba$_3$MA$_3$ (M = P, As, Sb, Bi; A = Cl, Br, I). These compounds are found to be dynamically and thermodynamically stable direct-gap semiconductors with G$_0$W$_0$@PBE+SOC band gaps spanning 1.23-2.17 eV. BSE calculations reveal moderate exciton binding energies (0.254-0.352 eV) and intermediate-radius excitons, while Fr\"ohlich polaron analysis indicates intermediate carrier-phonon coupling and mobilities up to $\sim$ 75 cm$^{2}$V$^{-1}$s$^{-1}$. The resulting spectroscopic limited maximum efficiencies reach $\sim$ 19-32%, surpassing several lead-based perovskites. Our results establish Ba-based antiperovskite derivatives as a robust, eco-friendly platform for next-generation optoelectronic devices.

cond-mat.mtrl-sci↗

arXiv2025

Decoding optoelectronic behavior in X$_3$BI$_3$ antiperovskite derivatives through many-body perturbation theory

Antiperovskite derivatives have emerged as promising candidates for optoelectronic applications. However, due to the significant computational cost, their excitonic and polaronic properties remain underexplored despite being critical for optoelectronic performance. Here, we present the structural, electronic, optical, excitonic, and polaronic properties of a series of antiperovskite derivatives with the chemical formula X$_{3}$BI$_{3}$ (X = Ca, Sr; B = P, As, Sb, Bi) using state-of-the-art first-principles calculations. All the compounds exhibit direct bandgaps with G$_{0}$W$_{0}$@PBE bandgap ranging from 2.42 to 3.02 eV, optimal for efficient light absorption with minimal energy loss. Exciton binding energies (0.258-0.318 eV) indicate moderate Coulomb attraction, favoring exciton dissociation. Employing the Feynman polaron model, we established the polaronic properties, where weak to intermediate carrier-phonon coupling was observed, with polaron mobilities reaching values up to 37.19 cm$^{2}$V$^{-1}$s$^{-1}$. These properties establish X$_{3}$BI$_{3}$ materials as viable candidates for next-generation optoelectronic devices.

cond-mat.mtrl-sci↗

arXiv2025

Unveiling the impact of trivalent metal cation transmutation on Cs$_{2}$AgM(III)Cl$_{6}$ double perovskites using many-body perturbation theory

Lead-free halide double perovskites A$_{2}$M(I)M(III)X$_{6}$ have garnered significant attention in the past decade as promising alternatives to CsPbX$_{3}$ perovskites, addressing concerns related to lead toxicity and material instability. In this work, we employ a trivalent metal cation transmutation strategy to design a series of inorganic Pb-free halide double perovskites Cs$_{2}$AgM(III)Cl$_{6}$ and perform a comprehensive investigation into their potential for applications in optoelectronic devices. Our first-principles calculations, rooted in density functional theory, demonstrate that these materials possess a face-centered cubic lattice structure while showcasing remarkable thermodynamic, dynamical, and mechanical stability. The G$_{0}$W$_{0}$@PBE electronic bandgap ranges from 1.47-6.20 eV, while the Bethe-Salpeter equation (BSE) indicates strong optical absorption spanning near-infrared to ultraviolet regions for these compounds. Furthermore, the excitonic properties suggest that these perovskites exhibit intermediate exciton binding energies (0.17 to 0.60 eV) and generally longer exciton lifetimes, except for the materials with M(III) = Sc, Y, Tb, and Lu. The Fr\"ohlich model indicates that these materials exhibit intermediate to strong carrier-phonon interactions, with hole-phonon coupling more prominent than electron-phonon coupling. Interestingly, the charge-separated polaronic states are found to be less stable than the bound exciton states, with higher polaron mobility for electrons (4.92-29.03 cm$^{2}$V$^{-1}$s$^{-1}$) than for holes (0.56-8.69 cm$^{2}$V$^{-1}$s$^{-1}$) in these materials. Overall, our study demonstrates that trivalent metal cation transmutation in Cs$_{2}$AgM(III)Cl$_{6}$ enables the creation of stable and lead-free halide double perovskites with exceptional, tunable optoelectronic properties, making them ideal for flexible optoelectronic applications.

cond-mat.mtrl-sci↗

arXiv2025

Soft mode induced structural phase transition in Ba$_2$ZnTeO$_6$ at high pressure

In this paper, we present a thorough investigation of vibrational, structural, and electronic properties of perovskite-type rhombohedral Ba$_2$ZnTeO$_6$ (BZTO) under systematic application of pressure. To carry out the analysis, we have performed pressure-dependent Raman spectroscopic measurements, synchrotron XRD, and density functional theory-based calculations. At ambient conditions, BZTO stabilizes in $R\bar{3}m$ space group, which under pressure undergoes a structural transition to a monoclinic phase with space group $C2/m$ at around 18~GPa. In-depth Raman analysis reveals softening of a phonon mode E$_g$ ($\sim $ 28cm$^{-1}$) leads to the structural phase transition. First principle DFT calculations also indicate that the doubly degenerate soft mode associated with the in-phase TeO$_6$ octahedral rotation drives the structure to a lower symmetry phase $C2/m$.

cond-mat.mtrl-sci↗

arXiv2025

Exploring 2D/Quasi-2D Ruddlesden-Popper Perovskite A$_{n+1}$Hf$_n$S$_{3n+1}$ (A = Ca, Sr, and Ba; n = 1-3) for Optoelectronics using Many-Body Perturbation Theory

Dimensionality engineering in A$_{n+1}$B$_n$X$_{3n+1}$ Ruddlesden-Popper (RP) perovskite phases has emerged as a promising strategy to enhance optoelectronic properties. These properties are highly material-dependent, requiring detailed exploration of electronic, optical, excitonic, transport, and polaronic characteristics. However, the absence of comprehensive studies continues to impede the rational design of high-performance materials. In this work, we investigate the excitonic and polaronic effects in A$_{n+1}$Hf$_n$S$_{3n+1}$ (A = Ca, Sr, and Ba; n = 1-3) RP phases, examining their relative stability and optoelectronic properties using several first-principles based methodologies within the framework of density functional theory and many-body perturbation theory (GW and BSE). Our study suggests that these compounds are mechanically stable and feature G$_0$W$_0$@PBE bandgaps ranging from 1.43 to 2.14 eV, which are smaller than those of their bulk counterparts. BSE and model-BSE (mBSE) calculations indicate that these RP phases display notable optical anisotropy, with the exciton binding energy decreasing as the thickness of the perovskite layer increases. In addition, intermediate to strong carrier-phonon scattering is observed in these compounds, confirmed through the Fr\"ohlich mechanism near room temperature. Using the Feynman polaron model, the polaron parameters of these RP phases are also computed, and it is found that charge-separated polaronic states are less stable than bound excitons. Finally, a significant increase in electron mobilities is observed in RP phases compared to their bulk counterparts. Overall, the insights gained from this study will enable the rational design of layered perovskite phases for applications in solar cells and other optoelectronic devices.

cond-mat.mtrl-sci↗

arXiv2025

Unlocking the Optoelectronic Potential of AGeX$_{3}$ (A = Ca, Sr, Ba; X = S, Se): A Sustainable Alternative in Chalcogenide Perovskites

The quest for environmentally benign and stable optoelectronic materials has intensified, and chalcogenide perovskites (CPs) have emerged as promising candidates owing to their non-toxic composition, stability, small bandgaps, large absorption coefficients. However, a detailed theoretical study of excitonic and polaronic properties of these materials remains underexplored due to high computational demands. Herein, we present a comprehensive theoretical investigation of Germanium-based CPs, AGeX$_{3}$ (A = Ca, Sr, Ba; X = S, Se), which adopt distorted perovskite structures (\beta-phase) with an orthorhombic crystal structure (space group : Pnma) by utilizing state-of-the-art density functional theory (DFT), density functional perturbation theory (DFPT), and many-body perturbation theory (GW and Bethe-Salpeter equation). Our calculations reveal that these materials are thermodynamically and mechanically stable, with the bandgaps calculated using G$_{0}$W$_{0}$@PBE ranging from 0.646 to 2.001 eV - suitable for optoelectronic devices. We analyze the ionic and electronic contributions to dielectric screening using DFPT and BSE methods, finding that the electronic component dominates. The exciton binding energies range from 0.03 to 73.63 meV, indicating efficient exciton dissociation under ambient conditions. Additionally, these perovskites exhibit low to high polaronic mobilities (1.67-167.65 cm$^{2}$V$^{-1}$s$^{-1}$), exceeding many lead-free CPs and halide perovskites due to reduced carrier-phonon interactions. The unique combination of wide tunable bandgaps, low exciton binding energies, and enhanced charge-carrier mobility highlights AGeX$_{3}$ as a potential material for next-generation optoelectronic applications. These compounds are stable, high-performing, and eco-friendly, showing great promise for experimental realization and device integration.

cond-mat.mtrl-sci↗

arXiv2025

Optimizing Lead-Free Chalcogenide Perovskites for High-Efficiency Photovoltaics via Alloying Strategies

Lead-free chalcogenide perovskites are emerging as game-changers in the race for sustainable, high-performance photovoltaics. These materials offer a perfect trifecta: non-toxic elemental composition, exceptional phase stability, and outstanding optoelectronic properties. However, unlocking their full potential for solar cell applications requires advanced strategies to fine-tune their electronic and optical behavior. In this study, we take CaHfS$_{3}$-a promising but underexplored candidate-and revolutionize its performance by introducing targeted substitutions: Ti at the cation site and Se at the anion site. Using cutting-edge computational techniques, including density functional theory, GW calculations, and the Bethe-Salpeter equation (BSE), we reveal how these substitutions transform the material's properties. Our findings highlight that alloyed compounds such as CaHfS$_{3-x}$Se$_{x}$ and CaHf$_{1-y}$Ti$_{y}$X$_{3}$ (X = S, Se) are not only phase-stable but also feature adjustable direct G$_{0}$W$_{0}$@PBE bandgaps (1.29-2.67 eV), reduced exciton binding energies, and significantly improved polaron mobility. These modifications enable better light absorption, reduced electron-hole recombination, longer exciton lifetimes, and enhanced quantum yield. Impressively, the alloyed perovskites, specifically, for the Ti-rich Se-based perovskites, achieve a spectroscopic-limited maximum efficiency of up to 28.06%, outperforming traditional lead-based halide perovskites. Our results demonstrate that strategic alloying is a powerful tool to supercharge the optoelectronic properties of lead-free chalcogenide perovskites, positioning them as strong contenders for next-generation photovoltaic technologies.

cond-mat.mtrl-sci↗

arXiv2024

Unveiling the structural, chemical state, and optical band-gap evolution of Ta-doped epitaxial SrTiO3 thin films using first-principles calculations and spectroscopic ellipsometry

In this report, the optical properties of Ta doped SrTiO3 (STO) due to its potential in transparent conducting oxides (TCOs) is explored by a combination of theoretical studies based on density functional theory and spectroscopic ellipsometry. To achieve this theoretically, we vary the concentration of Ta from 0 - 12.5% in SrTi1-xTaxO3 system by substitutional doping and report its effect on the resulting structural, chemical, electronic, chemical, and optical properties. Additionally, we perform band unfolding to shed light on the true nature of optical transitions due to Ta doping. We verify these results experimentally by fabricating epitaxial SrTi1-xTaxO3 thin films ( x = 0 - 5%) by pulsed laser deposition and obtain the optical dielectric properties of the system with the help of spectroscopic ellipsometry. By combining theoretical and experimental studies, we provide evidence that the band gap of STO increases due to Ta doping while also enhancing its electronic properties. The findings of our study offer an extensive understanding of the intricacies associated with elemental doping in perovskite oxides and propose strategies for addressing obstacles associated with TCOs.

cond-mat.mtrl-sci↗

arXiv2024

Unveiling the Optoelectronic Potential of Vacancy-Ordered Double Perovskites: A Computational Deep Dive

Lead-free perovskite materials have emerged as key players in optoelectronics, showcasing exceptional optical and electronic properties, alongside being environmentally friendly and non-toxic elements. Recently, among studied perovskite materials, vacancy-ordered double perovskites (VODPs) stand out as a promising alternative. In this study, we captured the electronic, optical, excitonic, and polaronic properties of a series of VODPs with the chemical formula Rb$_{2}$BX$_{6}$ (B = Si, Ge, Sn, Pt; X = Cl, Br, I) using first-principles calculations. Our results indicate these materials exhibit high stability and notable electronic and optical properties. The calculated G$_{0}$W$_{0}$ bandgap values of these perovskites fall within the range of 0.56 to 6.12 eV. Optical properties indicate strong infra-red to ultraviolet light absorption across most of the systems. Additionally, an analysis of excitonic properties reveals low to moderate exciton-binding energies and variable exciton lifetimes, implying higher quantum yield and conversion efficiency. Furthermore, utilizing the Feynman polaron model, polaronic parameters are evaluated, and for the majority of systems, charge-separated polaronic states are less stable than bound excitons. Finally, an investigation of Polaronic mobility reveals high polaron mobility for electrons (3.33-85.11 cm$^{2}$V$^{-1}$s$^{-1}$) compared to previously reported Cs-based VODP materials. Overall, these findings highlight Rb-based VODPs as promising candidates for future optoelectronic applications.

cond-mat.mtrl-sci↗

arXiv2024

Boosting the transparency of metallic SrNbO3 through Ti doping

In recent years, various materials have been developed to reduce the reliance of industries on Indium, a primary component of transparent conducting oxides (TCOs) used in the current generation of devices. The leading candidates for indium free TCOs are strontium vanadates, niobates and molybdates -- strongly correlated perovskite systems that exhibit high intrinsic electrical conductivity and optimal transparency. In this work, we focus on the strontium niobate thin films and manipulate its optical conductivity by Ti doping, which shifts the plasma frequency and reduces electronic correlations. This allows us to achieve a low resistance for Ti doped SNO thin films, while maintaining a high transparency in the visible spectrum. We obtain the optimal figure-of-merit (FOM) of 10.3 ($10^{-3}\Omega^{-1}$) for $x = 0.3$. This FOM significantly outperforms the optoelectronic capabilities of Tin-doped Indium oxide (ITO) and several other proposed transparent conductor materials. Our research paves the way for designing the next generation of transparent conductors, guided by insights from density-functional theory (DFT) and dynamical mean-field theory (DMFT).

cond-mat.mtrl-sci↗

arXiv2024

Post-Transition Metal Sn-Based Chalcogenide Perovskites: A Promising Lead-Free and Transition Metal Alternative for Stable, High-Performance Photovoltaics

Chalcogenide perovskites (CPs) have emerged as promising materials for optoelectronic applications due to their stability, non-toxicity, small bandgaps, high absorption coefficients, and defect tolerance. Although transition metal-based CPs, particularly those incorporating Zr and Hf, have been well-studied, they often exhibit higher bandgaps, lower charge carrier mobility, and reduced efficiency compared to lead-based halide perovskites (HPs). Tin (Sn), a post-transition metal with a similar oxidation state (+4) as Zr and Hf in ABX$_{3}$ structures but with different valence characteristics, remains underexplored in CPs. Given the influence of valence states on material properties, Sn-based CPs are of great interest. This study employs density functional theory (DFT), density functional perturbation theory (DFPT), and many-body perturbation theory (GW and BSE) to investigate a series of distorted Sn-based CPs (ASnX$_{3}$, A = Ca, Sr, Ba; X = S, Se). Our results demonstrate that these perovskites are mechanically stable and exhibit lower direct G$_{0}$W$_{0}$ bandgaps (0.79-1.50 eV) compared to their Zr- and Hf-based counterparts. Analysis of carrier-phonon interactions reveals that the charge-separated polaronic state is less stable than the bound exciton state in these materials. Additionally, polaron-assisted charge carrier mobilities for electrons (21.33-416.02 cm^{2}V^{-1}s^{-1}) and holes (7.02-260.69 cm^{2}V^{-1}s^{-1}) are comparable to or higher than those in lead-based HPs and significantly exceed those of Zr- and Hf-based CPs, owing to reduced carrier-phonon coupling. The estimated spectroscopic limited maximum efficiency (24.2%-31.2%)-confirmed through perovskite solar cell (PSC) simulations using SCAPS-1D software-indicates that these materials are promising candidates for photovoltaic applications.

cond-mat.mtrl-sci↗

arXiv2024

Probing Optoelectronic Properties of Stable Vacancy-Ordered Double Perovskites: Insights from Many-Body Perturbation Theory

A$_{2}$BX$_{6}$ vacancy-ordered double perovskites (VODPs) have captured substantial research interest in the scientific community as they offer environmentally friendly and stable alternatives to lead halide perovskites. In this study, we investigate Rb$_{2}$BCl$_{6}$ (B = Ti, Se, Ru, Pd) VODPs as promising optoelectronic materials employing state-of-the-art first-principles-based methodologies, specifically density functional theory combined with density functional perturbation theory (DFPT) and many-body perturbation theory [within the framework of GW and BSE]. Our calculations reveal that all these materials possess a cubic lattice structure and are both dynamically and mechanically stable. Interestingly, they all exhibit indirect bandgaps, except Rb$_{2}$RuCl$_{6}$ displays a metallic character. The G$_{0}$W$_{0}$ bandgap values for these compounds fall within the range of 3.63 to 5.14 eV. Additionally, the results of the BSE indicate that they exhibit exceptional absorption capabilities across the near-ultraviolet to mid-ultraviolet light region. Furthermore, studies on transport and excitonic properties suggest that they exhibit lower effective electron masses compared to holes, with exciton binding energies spanning between 0.16$-$0.98 eV. We additionally observed a prevalent hole-phonon coupling compared to electron-phonon coupling in these compounds. Overall, this study provides valuable insights to guide the design of vacancy-ordered double perovskites as promising lead-free candidates for future optoelectronic applications.

cond-mat.mtrl-sci↗

arXiv2022

ScS_{2} Monolayer as a Potential Cathode Material for Alkali-ion Batteries and Beyond

Sc is the lightest transition metal that could help to achieve the goal of high theoretical capacity. Hence, we here explored the performance of ScS_{2} monolayer as a cathode material for alkali-ion batteries (Li, Na, K) and other multi-valent metal-ion batteries (Mg, Al). Previous studies on ScS_{2} have focused only on the fundamental electronic and magnetic properties of the ScS_{2} monolayer, but not on its possible applications. Our first-principles calculations show that 2D ScS_{2} is able to deliver a large theoretical capacity of 491.36 mAh g^{-1} for alkali-ions and 324.29 mAh g^{-1} for Mg and Al-ions while maintaining good average open-circuit voltages. We also studied the diffusivity of these metal ions on the ScS_{2} surface which is related to the charge/discharge rate capability of batteries. Our results suggest low diffusion barriers for all metal ions except Al. Owing to these results, we, therefore, believe that the ScS_{2} monolayer can be an interesting candidate for cathode material to be used in alkali-ion batteries and beyond.

cond-mat.mtrl-sci↗

arXiv2018

Comment on "Structure Prediction of Li-Sn and Li-Sb Intermetallics for Lithium-Ion Batteries Anodes''

In a recently published article Mayo et al.[Chemistry of Materials 2017, 29, 5787] presented the ground state crystal structures of various experimentally unknown Li-Sn intermetallic compounds at ambient pressure (~0 GPa) and 0 K temperature using ab-initio random structure searching method (AIRSS) with high-throughput screening from the Inorganic Crystal Structure Database (ICSD).\cite{AIRSS} In their study, besides the experimentally known phases of Li-Sn such as, $\mathrm{Li_{2}Sn_{5}}$ ($\mathrm{P4/mbm}$),$\mathrm{Li_{1}Sn_{1}}$ ($\mathrm{P2/m}$, $\mathrm{I4_{1}/amd}$), $\mathrm{Li_{7}Sn_{3}}$ ($\mathrm{P2_{1}/m}$), $\mathrm{Li_{5}Sn_{2}}$ ($\mathrm{R\bar{3}m}$), $\mathrm{Li_{13}Sn_{5}}$ ($\mathrm{P\bar{3}m1}$), $\mathrm{Li_{7}Sn_{2}}$ ($\mathrm{Cmmm}$), and $\mathrm{Li_{17}Sn_{4}}$ ($\mathrm{F\bar{4}3m}$), Mayo et al. also reported two previously unknown stable phases for Li-Sn such as, $\mathrm{Li_{8}Sn_{3}}$-$\mathrm{R\bar{3}m}$ and $\mathrm{Li_{7}Sn_{2}}$-$\mathrm{P\bar{1}}$ along with several Li-Sn metastable phases ($\mathrm{Li_{1}Sn_{2}}$, $\mathrm{Li_{2}Sn_{3}}$, $\mathrm{Li_{7}Sn_{9}}$, $\mathrm{Li_{3}Sn_{2}}$, $\mathrm{Li_{5}Sn_{3}}$, $\mathrm{Li_{2}Sn}_{1}$, $\mathrm{Li_{3}Sn_{1}}$, $\mathrm{Li_{4}Sn_{1}}$, $\mathrm{Li_{5}Sn_{1}}$, and $\mathrm{Li_{7}Sn_{1}}$) which lie within 20 meV/atom from the convex hull tie-line. However, while going through their article, we noticed a significant inconsistency and contradictions in their results. Moreover, a one-to-one comparison with our published results\cite{Sen@2017} revealed a disagreement in the symmetry of $\mathrm{Li_{3}Sn_{1}}$, $\mathrm{Li_{7}Sn_{2}}$, $\mathrm{Li_{4}Sn_{1}}$, $\mathrm{Li_{5}Sn_{1}}$, and $\mathrm{Li_{7}Sn_{1}}$ discussed by Mayo et al.}

cond-mat.mtrl-sci↗

arXiv2016

Pressure Induced Thermodynamically Stable and Mechanically Robust Li-rich Unknown Li-Sn Compounds: A Step Towards Improvement of Li-Sn Batteries

Volume expansion and elastic softening of Sn anode on lithiation result in mechanical degradation and pulverization of Sn, affecting the overall performance of Li-Sn batteries. It can however be overcome by using exotic high pressure quenched phase as prelithiated reagent. Moreover, it is known that under pressure many unusual stoichiometric which are basically impossible at ambient pressure, can be synthesized, that may even survive the decompression from high to ambient pressure.We therefore have performed a comprehensive study using evolutionary algorithm and density functional theory based simulations to understand the lithiation of Sn anode at pressure ranging from 1 atm to 20 GPa. The ground state structures of all stable and metastable Li-Sn compounds have been identified at ambient and moderate pressures and their properties have been studied to understand the role of pressure in re-defining the reaction mechanism during charging-discharging process in Li-ion batteries. Besides the well-known existing Li-Sn compounds, our studies reveal the existence of five unreported stoichiometries (Li8Sn3, Li3Sn1, Li4Sn1, Li5Sn1, and Li7Sn1) and their associated crystal structures at ambient and high pressure. While Li8Sn3 has been identified as one of the most stable Li-Sn compound in the entire pressure range (1 atm-20 GPa), the pressure induced Li-rich compounds like Li5Sn1 and Li7Sn1 have been classified as providing higher theoretical gravimetric capacity of 1129 and 1580 mAh/g), respectively, than the capacity of the known most lithiated phase, i.e., Li17Sn4 (960 mAh/g).Most importantly, our calculations show reduction in volume expansion by ~ 50% at 20 GPa, and reveal that the application of pressure can reduce the chance of Li plating and improve the mechanical properties, which are desired to make the battery safer and its life longer.

cond-mat.mtrl-sci↗