We have reported electronic and thermoelectric properties of non-centrosymmetric topological half-Heusler compound LuPtBi with LSDA and LSDA+SOC (Spin-orbit coupling) approximation which is implemented in density functional theory (DFT). Due to implication of spin-orbit coupling the degeneracy of electronic bands near the fermi level is removed and Density of states (DOS) gets decreased. Partial density of states showed significant contribution from Pt-d orbital to valence band and Lu-d orbital to conduction band. Slope of electronic band near fermi level signifies appreciable change in Seebeck co-efficient S[V/K] with LSDA+SOC approximation at temperature 760K.This makes LuPtBi as a promising candidate for thermoelectric applications.

The structural and electronic properties of TmGa3 magnetic compound which crystallizes in AuCu3-type structure are studied using first principles density functional theory based on full potential linearized augmented plane wave (FP-LAPW) method. The calculations are carried out within the Local Spin Density Approximation (LSDA) for the exchange correlation potential. Our calculated ground state property such as lattice constant (ao) is in good agreement with the experimental value. The computed electronic band structures and density of states reveal the metallic character of this compound.

The structural, electronic, elastic, mechanical, Fermi surface, and electronic charge density properties of the magnetic intermetallic compound HoGa₃, crystallizing in the cubic AuCu3-type structure, have been investigated using first-principles Density Functional Theory (DFT) within the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method. The calculations were performed using both the Local Spin Density Approximation (LSDA) and LSDA+U schemes to account for the strong correlation effects of the Ho-4f electrons. The equilibrium lattice parameter, bulk modulus, and its pressure derivative were determined from total energy calculations, and the obtained lattice constant is found to be in good agreement with available experimental data. The electronic band structure and density of states analyses reveal the metallic nature of HoGa3, with significant contributions from Ho-4f states near the Fermi level. The inclusion of the Hubbard U parameter improves the description of the localized 4f states and enhances spin-polarization effects. The calculated elastic constants satisfy the mechanical stability criteria for cubic crystals, confirming the structural stability of the compound. Electronic charge density maps indicate predominantly metallic bonding with weak directional interactions between neighboring atoms. Furthermore, the spin-polarized Fermi surface exhibits a complex multiband topology comprising both electron and hole pockets, suggesting the coexistence of multiple charge carriers. These results provide a comprehensive understanding of the structural stability, electronic structure, mechanical behavior, and transport characteristics of HoGa3, offering valuable insights for future investigations of rare-earth intermetallic compounds.

The structural and electronic properties of isostructural and isoelectronic magnetic TmAl3 intermetallic compound, which crystallize in AuCu3-type structure, are studied using first principles density functional theory based on full potential linearized augmented plane wave (FP-LAPW) method. The calculations were performed using LSDA for the exchange correlation potential. Our findings for ground state properties such as lattice constant (a(0)), bulk modulus (B), and its pressure derivative (B') are consistent with existing experimental and theoretical data. The calculated electronic band structure and density of states (DOS) indicates that the compound exhibits metallic properties.

An investigation has been conducted on structural and electronic characteristics of cubic half heusler compound AcOF. The FP-LAPW approach is used in density functional theory (DFT) to conduct the investigation. GGA scheme was applied to verify the structural stability. The lattice parameter, unit cell volume, bulk modulus, and pressure derivative of bulk modulus are among the ground-state characteristics that are calculated. The calculated GGA lattice parameters correlate well with the available data. Band structure, density of state and charge density have been plotted. Electronic band structure confirms AcOF as an insulator having large band gap.

This work reports the theoretical investigation of the effect of incorporation of dilute Bismuth (Bi) on the optical and electronic properties of zinc blende (ZB) phase Indium Phosphide (InP) using the full-potential linearized augmented plane wave (FP-LAPW) basis set, Perdew-Burke-Ernzerhof (PBE) exchange-correlation (XC) function, and the Tran Blaha modified Becke-Johnson (TB-mBJ) potential in the density functional theory (DFT) computational framework. The obtained results show that the introduction of large-sized Bi impurities into InP increases the lattice constant and reduces the bandgap by 52 meV/Bi%. We have also presented the design of an InP/InP1_xBix/InP planar solar cell (SC) utilizing the computed optical and electronic properties of the investigated InP1-xBix alloy to produce SC with an average absorptance of 65.14% and 62.91% with Bi incorporation of 3.125% and 6.25%, respectively, and an optical current density (Jopt) of 29.45 mA/cm2 for Bi concentration of 6.25%. We also thoroughly analyzed two additional parameters, namely the electric field distribution and photogeneration rate. By adding 6.25% Bi into InP, we obtained a band gap of 1 eV, which is perfect for SC design. With this SC, we got the highest short-circuit current density (Jsc) of 23.23 mA/cm2 and power conversion efficiency (PCE) of 14.53 %.

We have reported electronic and thermoelectric properties of YPdBi with PBE-GGA and PBE-GGA+SOC (Spin-orbit coupling) approximation which is implemented in density functional theory (DFT). Incorporation of spin-orbit coupling splits the degenerate band near the fermi level and Density of states (DOS) gets decreased. Band inversion is observed with PBE-GGA+SOC which signifies non-trivial topological semi-metallic behaviour of YPdBi. Thermoelectric properties such as Seebeck coefficient S[V/K] and thermoelectric figure of merit ZT also becomes appreciable at high temperature with the inclusion of SOC. This makes YPdBi a sound candidate for thermoelectric applications.

We have reported the electronic and thermoelectric properties of rare-earth half-Heusler XPtBi(X = Gd,Nd,Y) topological semimetals(TSMs)compounds from the perspective of density functional theory. We have reported that the inclusion of spin orbit coupling (SOC) made more dense bands near fermi level which will be able to tune the electronic bands and well controlled twisting of the spin order which is mostly applicable to spintronic applications. Our results show that the band gap crossing is more near fermi level by the inclusion of SOC. We have reported that LSDA + U has strong effect on unfilled X-f states and hence shifts the bands towards Fermi level. We have found different topological states in these compounds in spin up and spin down states for GdPtBi, NdPtBi and YPtBi. We have further reported the transport properties of these TSMs with and without SOC in terms of figure of merit. Our results confirm that with the inclusion of SOCs in YPtBi power factor get enhanced appreciably for thermoelectric uses.

Understanding nanomaterials is a training tool for the future workforce in nanotech development. Significant research employing nanomaterials has been conducted in the field of nanotechnology over the past few years. Nanomaterials are cornerstones of nanoscience and nanotechnology. Due to great potential to provide societal benefits, nanostructured materials are a topical focus for researchers and worldwide. Nanomaterials have special optical, magnetic, electrical, physical, reactivity, strength, surface area, sensitivity, and stability features. Nanomaterials are usually considered to be materials with at least one external dimension that measures 100 nanometres. The aim of this chapter is to enable researchers to understand in an easy and more rapid manner the state of the art, and thereby develop relevant new information for the research and development communities. This chapter is followed by (i) introduction, (ii) classification of nanomaterials, (iii) applications of nanomaterials, and (iv) future aspects and challenges of nanomaterials.

The electronic structure, phase transition pressure and mechanical properties of light rare-earth bismuthides (PrBi, NdBi, PmBi and SmBi) have been investigated by full geometry optimization using Vienna Ab-Initio Simulation Package (VASP) which has been used in combination with the projector augmented wave (PAW) method and the generalized gradient approximation (GGA) over the local density approximation (LDA) for exchange-correlation functional. We focus our attention on the lattice constants and elastic constants of these compounds. These compounds undergo a phase transition from the NaCl (B1) structure to the body-centered tetragonal (BCT) structure. We also report the density of states (DOS) of these rare earth bismuthides. In the case of PrBi and NdBi, the 4f states are treated as valence states. The effects of on-site Coulomb repulsion and the spin-orbit coupling (SOC) on the electronic structure are also studied.

Halide perovskites have recently emerged as promising materials for low-cost, high-efficiency solar cells. The unique optoelectronic properties of perovskites include high optical absorption, high carrier mobility, long diffusion lengths, and unique ambipolar charge transport properties. Over the last two decades, halide perovskites (HPs) have been identified as one of the most promising materials in photovoltaic and light-emitting devices. Halide perovskites can be synthesized easily. Therefore, these materials are expected to be highly scalable for a variety of applications. This will require extensive research, from the basic properties to practical devices. This chapter makes an effort to highlight the advancements made in the perovskite materials for Photovoltaics cell and lighting in the recent years.

For energy-efficient thin-film solar cells, photovoltaic researchers are investigating alternative strategies like metallic nanostructures supporting plasmon resonance and ultrathin coatings of antireflective materials to minimize optical absorption loss. To reduce the reflection losses from the surface of the solar cells (SCs), optimizing the dimensions of the metallic nanostructures and antireflection coating (ARC) is essential. A systematic step-by-step approach is used to gain scientific insights into improving the planar GaAs SC performance. In this article, device performance optimization of a solar cell was studied with five distinct architectures, namely, planar GaAs, GaAs with metal nanoparticle (MNP) on top, GaAs coated with ARC, GaAs with MNP over ARC, and GaAs with MNP embedded in ARC using the finite element method. To analyze the effect of ARC thickness and MNP size on optical characteristics, the optical short-circuit current density (Jopt) is computed using absorptance data as the performance parameter. We used various metals on the GaAs/Al architecture to choose MNP materials, and titanium (Ti) nanoparticles were chosen because they have the maximum Jopt. For ARC, we have chosen three oxides, Ta2O5, MoO3, and ZnO, and two polymeric materials, P3HT and PEDOT:PSS. We have compared the optical performance of the different optimized architectures using Jopt, absorption spectra, electric field, and photogeneration rate. This exhaustive analysis shows that Ti MNPs with a diameter of 180 nm and P3HT ARC with an 80 nm thickness, placed over GaAs planar structure, deliver maximum Jopt values of 29.87 and 27.67 mA/cm2, respectively. Further, to understand the dual impact of plasmons and ARC, we simultaneously varied the MNP size and the ARC thickness and found that GaAs planar structure coated with 10 nm thick MoO3 and Ti plasmon with diameter of 160 nm has the best Jopt of 29.66 mA/cm2. Secondly, we embedded Ti plasmons of 60, 120, and 180 nm diameters into the ARC film and found that MNPs enhance photocurrent. It is observed that Ti MNPs with an optimized diameter of 180 nm embedded in a 40 nm thick MoO3 ARC and placed directly over the GaAs structure deliver the highest Jopt of 30.45 mA/cm2. This comprehensive analysis can help researchers to improve the GaAs SC efficiency using the combined effect of geometrically optimized ARCs and MNPs.

In this manuscript, a thorough comparative analysis of six GaAs based nanostructures (hollow and solid) is performed on the basis of their optical performance. These nanostructures are known to exhibit excellent anti-reflection properties, owing to their ability to generate a broadband absorption spectrum through efficient photon harvesting. Using the Finite Element Method (FEM) of the commercially available COMSOL Multiphysics package, the absorption characteristics, optical short circuit current density (J SC ), electric field and photogeneration rates of six different nanostructures namely concentric nanocylinder (CNCy), hollow concentric nanocylinder (HCNCy), inverted nanopencil (INPe), hollow nanopencil (HNPe), nanorod + nanohemisphere (NR + NHe), and hollow nanorod + hollow nanohemisphere (HNR + HNHe) are computed. The optical performance of these nanostructures is largely dependent on their geometrical parameters such as filling ratio (FR = Diameter/Period), spacing and structural dimensions. The optimized values of these parameters can play a vital role in capturing the optical resonance modes by the nanostructures to produce absorption enhancement. It has been observed that the nanostructures with base diameter of 240 nm, period in the range of 300–350 nm and FR of 0.8 exhibit better optical characteristics. Optical J SC and optical efficiency of 29.45 mA cm −2 and 42.26%, respectively for CNCy nanostructure with FR of 0.8 and diameter of 240 nm is the highest among all the nanostructures. The effect of the angle of incidence of the photons striking the nanostructures on the average absorptance in both Transverse Electric (TE) and Transverse Magnetic (TM) modes are also investigated. In addition to this, we have also computed the effective refractive index for all the nanostructures using Maxwell Garnett formula in order to estimate the surface anti-reflection characteristics of these nanostructures.

This article aims to increase light absorption and improve efficiency by using antireflection coatings on solar cells. Optical losses owing to the reflection of the incident photons from the solar cell (SC) surface are one of the most significant factors affecting the efficiency of the SCs. In this work, two cases were considered: GaAs planar structure without antireflection coating (ARC) and the other with four different ARCs in the form of ZnO, PEDOT: PSS, Ta 2 O 5 , and MoO 3 . Simulation of the structures is done using the Wave Optics Module of COMSOL Multiphysics. The optical characteristics of the coated and uncoated ultrathin solar cells are analysed from wavelength 300 to 870 nm. The optical properties, such as absorptance (A(λ)), optical JSC, electric field (E-field), and photogeneration rates (Gopt) are computed to understand the optical trapping effects of the investigated structures. For the optimized thickness of 90 nm for ZnO and PEDOT: PSS ARC over GaAs ultrathin SC, the reflection losses are 68 % and 60.8 %, respectively lower than the planar ultrathin structure. Out of all the investigated structures, ZnO-coated GaAs ultrathin SC recorded highest optical JSC of 26.89 mA/cm 2 and 31.6% higher absorption as compared to planar GaAs structure.

We have reported the mechanical properties of topological semimetals half-Heusler compound YPtBi with LDA and GGA approximation which is implemented in density functional theory. We have calculated elastic parameters which ensure good machinability, covalent bonding, brittleness, low value of Kleinman parameter and high Vickers hardness. Our results reveal the hardness or large resistance of these topological semimetals. Moreover, Born mechanical stability conditions are well fulfilled by the topological semimetal YPtBi. Present study reveals that the low value of bulk modulus and shear modulus wheras high value of Youngs modulus of this topological semimetals which deforms easily with applied external force. We have also calculated optical properties of topological semi-metal YPtBi with both LDA and GGA. Optical properties are calculated in terms of dielectric function and we have calculated dielectric constant, optical reflectivity, absorption co-efficient, optical conductivity, refractive index and electron energy loss in the energy range 0 – 14 eV. We have found higher dielectric constants with GGA in comparison to LDA that imply YPtBi is excellent materials in solar cell applications. Also, YPtBi possess high refractive index in the visible range and it is optically isotropic.

In this article, we have performed a comparative analysis of six different types of nanostructures that can improve photon management for photovoltaic applications. These nanostructures act as anti-reflective structures by improving the absorption characteristics and tailoring the optoelectronic properties of the associated devices. The absorption enhancement in indium phosphide (InP) and silicon (Si) based cylindrical nanowires (CNWs) and rectangular nanowires (RNWs), truncated nanocones (TNCs), truncated nanopyramids (TNPs), inverted truncated nanocones (ITNCs), and inverted truncated nanopyramids (ITNPs) are computed using the finite element method (FEM) based commercial COMSOL Multiphysics package. The influence of geometrical dimensions of the investigated nanostructures such as period (P), diameter (D), width (W), filling ratio (FR), bottom W and D (Wbot/Dbot), and top W and D (Wtop/Dtop) on the optical performance are analyzed in detail. Optical short circuit current density (Jsc) is computed using the absorption spectra. The results of numerical simulations indicate that InP nanostructures are optically superior to Si nanostructures. In addition to this, the InP TNP generates an optical short circuit current density (Jsc) of 34.28 mA cm-2, which is ∼10 mA cm-2 higher than its Si counterpart. The effect of incident angle on the ultimate efficiency of the investigated nanostructures in transverse electric (TE) and transverse magnetic (TM) modes is also explored. Theoretical insights into the design strategies of different nanostructures proposed in this article will act as a benchmark for choosing the device dimensions of appropriate nanostructures for the fabrication of efficient photovoltaic devices.