Figure Of Merit Research Articles

Large thermoelectric transport in magnetically coupled CrI3/1T-MoS2 vdW heterostructure via spin–charge interconversion

Low-dimensional materials with prominent thermoelectric (TE) effect play a pivotal role in realizing state-of-the-art nanoscale TE devices. The fusion of TE effect with the magnetism through seamless integration of TE and magnetic materials in the 2D limit offers access to control longitudinal as well as transverse TE properties via magnetic proximity effect. Herein, we design a van der Waals (vdW) heterostructure of metallic 1T-MoS2 with promising TE properties and a layer-dependent magnetic CrI3 material. The result highlights exotic electronic and magnetic configurations of the designed monolayer-CrI3/1T-MoS2 vdW heterostructure, which show magnetically-coupled TE characteristics. The observed remarkable magnetic proximity stems from large magnetic anisotropy energy and spin polarization, which are found to be 2.21 meV Cr−1 and 12.30%, respectively. To this end, the semiconducting CrI3 layer with intrinsic magnetism leads to efficient control and tunability of the observed spin-correlated anomalous Nernst effect. Moreover, a large dimensionless figure of merit of ∼6 and a power factor of ∼3.8×1011/τ∘ Wm−1K−2s−1 near the Fermi level at 300 K endorse the rejuvenated TE effect. The strong relativistic spin–orbit coupling validates the significant correlation of TE properties with intrinsic magnetic configuration. The present study underscores the significance of the magnetic proximity-governed TE effect in vdW heterostructures to engineer low-dimensional TE devices.

Core@shell strategies to enhance green upconversion emission of LaAlO3:ErIII, YbIII nanoparticles

Seeking enhanced luminescence in upconverter nanoparticles, LAO:ErIII0.01, YbIII0.01, LAO = LaAlO3, with an average diameter of 30–40 nm, was synthesized via a modified Pechini method. Two coating strategies were employed: the first with three layers of 1 % LAO, and the second with LAO:NdIIIx at% (x = 10 or 30) or LAO:NdIIIx at%, YbIIIy at% (x, y = 30, 2 or 30, 20). Characterization included FTIR, UV–Vis diffuse reflectance, TEM, XRD, and photoluminescence. In the first strategy, undoped phase coating maintained the LaAlO3 rhombohedral crystalline structure, enhancing ErIII core emission under 980 nm laser excitation. In the second case, the shell containing YbIII (3 or 20 at%) under laser at 808 nm, favored the increase in the relative emission intensity of the activator, exciting ErIII directly in the core or via the outer NdIII sensitizer. Kinetic measurements fixing excitation at 980 nm and emission at 542.5 nm resulted in ErIII excited state decay values between 56 and 68 μs. The doped shell favored increased excited state lifetimes, exhibiting concentration quenching in the 30 % YbIII condition. Both NdIII presence and its combination with YbIII enhanced green emission compared to the uncoated core. From thermometric studies, the successive depositions of inert layers of LAO contributed to the highest relative thermal sensitivity of 1.79 % K−1 at 305 K, among the systems studied. Therefore, the core@shell strategies were successful in intensifying ErIII emission, both in the green and red regions, and resulted in relevant figures of merit that qualify them for applications in nanothermometry in the biological window.

Supramolecular solvent-based liquid–liquid microextraction (SUPRAS-LLME) of Sudan dyes from food and water samples with HPLC

Utilizing the environmentally friendly technique of supramolecular solvent-based microextraction (SUPRAS-LLME), Sudan I-IV dyes were successfully isolated and enriched from food and natural water samples. The optimization of the microextraction process was carried out by studying the effects of various parameters such as pH (6.0), supramolecular volume (100 μL), tetrahydrofuran (THF) volume (200 μL), ultrasonication temperature (40 °C), and vortex time (1.0 min). Extraction efficiency ranged between 82 % and 109 %, while other analytical parameters such as the limits of detection (LOD) were determined to be 0.23, 0.51, 0.42, and 0.39 μg L−1 for Sudan I, II, III, and IV, respectively. The total figure of merits for the presented SUPRAS-LLME method includes a limits of quantification (LOQ) of 0.78, 1.70, 1.41, and 1.30 μg L−1, a relative standard deviation (RSD%) of 3.4, 6.1, 2.9, and 4.4 (n = 10), a linear range of 5–1000 μg L−1 for all Sudan dyes, a pre-concentration factor (PF) of 15, 10, 10, and 17, and a determination coefficient (R2) of 0.9994, 0.9965, 0.9955, and 0.9946, for Sudan I, II, III, and IV, respectively. The environmental friendliness of the method was confirmed by evaluating the greenness of the method with the AGREE metric tool. A sustainable and environmentally friendly option for the extraction of Sudan dyes from food and water samples is offered by this SUPRAS-LLME method.

A First-Order Noise-Shaping SAR ADC with PVT-Insensitive Closed-Loop Dynamic Amplifier and Two CDACs

This paper presents a first-order noise-shaping (NS) successive approximation register (SAR) analog-to-digital converter (ADC) with a process, (supply) voltage, and temperature (PVT)-insensitive closed-loop integrator and data-weighted averaging (DWA). The use of a cascode floating inverter amplifier (FIA)-type dynamic amplifier with high gain enables an aggressive noise transfer function while minimizing the power consumption associated with the use of an active filter. In the proposed ADC, the residue is generated by a capacitive digital-to-analog converter (CDAC) employing DWA, which is made possible by employing a second CDAC, which operates after the SAR operation is completed. The proposed ADC is designed with a 28 nm CMOS process with 1 V power supply. The simulation results show that the ADC achieves the SNDR of 71.2 dB and power consumption of 228 μW when operated with a sampling rate of 80 MS/s and oversampling ratio (OSR) of 10. The Schreier figure-of-merit (FoM) is 173.6 dB, and Walden FoM is 9.6 fJ/conversion-step.

An Energy-Efficient 12-Bit VCO-Based Incremental Zoom ADC with Fast Phase-Alignment Scheme for Multi-Channel Biomedical Applications

This paper presents a low-power, energy-efficient, 12-bit incremental zoom analog-to-digital converter (ADC) for multi-channel bio-signal acquisitions. The ADC consists of a 7-stage ring voltage-controlled oscillator (VCO)-based incremental ΔΣ modulator (I-ΔΣM) and an 8-bit successive approximation register (SAR) ADC. The proposed VCO-based I-ΔΣM can provide fast phase-alignment of the ring-VCO to reduce the interval settling time; thereby, the I-ΔΣM can accommodate time-division-multiplexed input signals without phase leakage between consecutive measurements. The SAR ADC also adopts splitting unit capacitors that can support VCM-free tri-level switching and prevent invalid states from the phase frequency detector with minimal logic gates and switches. The proposed ADC has been fabricated in a standard 180 nm standard 1P6M CMOS process, exhibiting a 67-dB peak signal-to-noise ratio, a 74-dB dynamic range, and a Walden figure of merit of 19.12 fJ/c-s, while consuming a power of 3.51 μW with a sampling rate of 100 kS/s.

Double ultraviolet to visible high-Q magnetic plasmon induced reflection with ultralarge Rabi splitting for optical detecting

We theoretically explore double ultraviolet (UV) to visible high-Q magnetic plasmon induced reflections (PIRs) through the coupling between the fundamental magnetic plasmon (MP) mode in single aluminium (Al) nanogroove and the first (second) order surface plasmon polaritons (SPPs) launched by periodic nanogroove arrays, which is predicted analytically by a Fano interference model. The ultrastrong coupling effects between MP and SPP with ultralarge Rabi splitting energy up to 868 meV and 842 meV are obtained in the UV and visible ranges. Due to the high Q-factors of the double PIRs, a significant slow light effect is achieved with the group index up to 65 and 77 in the UV and visible ranges, respectively. The double PIRs show the high sensitivity of 510 nm/RIU and the figure of merit (FoM) of 42, and could be used to monitor analyte layer with a few nanometers, suggesting great potential for label-free biosensing.

Enhancement of alpha/beta ratio in NaI:Tl,6Li neutron-gamma scintillators by rare earth co-doping

NaI:Tl,6Li bulk crystals are regarded as promising neutron-gamma (n-γ) scintillators because of low production cost and superior n-γ pulse shape discrimination (PSD) performance. In this work, some rare earth elements (Gd, Y, Lu and Sc) co-doped NaI:Tl,6Li single crystals were grown by the multi-ampoule Bridgman method. It was found that the rare earth co-doping significantly improves the pulse height discrimination (PHD) capability of NaI:Tl,6Li with high alpha/beta (α/β) ratio, approaching to 100%. The optimal α/β ratios achieved for Gd, Y, Lu and Sc co-doped NaI:Tl,6Li are 0.85, 0.93, 0.95, and 0.83, respectively. Electron equivalent energy per neutron interaction is above 3.96 MeV and can be as high as 4.54 MeV, close to the Q value of 4.78 MeV for 6Li(n, α)3H interaction. Moreover, the rare earth co-doped NaI:Tl,6Li crystals still maintain the superior PSD capability with figure of merit (FoM) in the range of 2.1-3.3. These results highlight the great potential of rare-earth co-doped NaI:Tl,6Li crystals serving as high-performance n-γ scintillators.

Optical switching with high-Q Fano resonance of all-dielectric metasurface governed by bound states in the continuum

The discovery of bound states in the continuum (BIC) of optical nanostructures has garnered significant research interest and found widespread application in the field of optics, leading to an attractive approach to achieve high-Q (Quality factor) Fano resonance. Herein, an all-dielectric metasurface consisting of four gallium phosphide (Gap) cylinders on the MgF2 substrate is designed and analyzed by the finite element method (FEM). By breaking the symmetry of the plane, specifically by moving the two cylinders to one side, it is possible to achieve a transition from the symmetry-protected BIC to quasi-BIC. This transition enables the excitation of sharp dual-band Fano resonance at wavelengths of 1,045.4 nm and 1,139.6 nm, with the maximum Q factors reaching 1.47 × 104 and 1.28 × 104, respectively. The multipole decomposition and near-field distributions show that these two QBICs are dominated by the electric quadrupole (EQ) and magnetic quadrupole (MQ). Furthermore, bidirectional optical switching can be accomplished by changing the polarization direction of the incident light. As a result, the maximum sensitivity and figure of merit (FOM) are 488.9 nm/RIU and 2.51 × 105 RIU−1, respectively. The results enrich our knowledge about BIC and reveal a platform for the development of high-performance photonics devices such as optical switches and sensors.

Improvement in the opto-thermal performance of Indian standard solar box cooker by novel internal retrofit radiative control

Design intervention for improvement in the performance of a solar cooker is required for its mass adoption and popularization. It has remained stagnant for decades for want of a holistic tool which provides metric for prediction of its cumulative optical and thermal(opto-thermal) performance, cooking type/objectives, techno-economic feasibility and climatic impact/carbon mitigation potential. In this work assessment of effectiveness of novel design intervention through retrofitting of internal radiative control in an Indian solar box cooker, one of the most popular family cookers in India, has been investigated using available tools. The solar cooker, with the minimal design intervention, and negligible cost implication shows an improvement of 6.74%, and 6.86% in the values of figures of merit, F1 and F2, respectively, used for the thermal performance evaluation. Here, the standard test procedure for figures of merit mainly accounts for the thermal aspect of the performance as it excludes the use of external booster reflector. Alternatively, the Cooker opto-thermal ratio (COR), a parameter measuring opto-thermal performance, shows a 1.25-fold increase. The retrofitted reflectors enhance localised targeted absorption and reduce thermal losses, resulting in a 25% improvement in COR. The retrofitting process is simple, and easy; and offers superior performance, favourable economics, and potential for carbon mitigation, making it highly attractive. Also, this work demonstrates COR as a tool with higher resolution enabling analysis of the impact of even minimal design intervention.

Impact of blade shape on the aerodynamic performance and turbulent jet dynamics produced by a ducted rotor

A ducted rotor system was used to produce turbulent jets with a Reynolds number up to 5.97 × 105 and Mach number of 0.222 based on mean streamwise velocity. Three rotors with a diameter of 11.8 cm were manufactured and tested inside a duct with a 1 mm tip clearance at a speed up to 30 000 revolutions per minute (rpm). All rotor blades contain the same aspect ratio of 2.2, a National Advisory Committee for Aeronautics 2410 airfoil, and ideal pitch distribution. However, three different blade planform shapes were used including a rectangular shape with constant chord, trapezoidal shape with a taper ratio of 0.5, and elliptical shape where the trailing edge of the blade is expressed with an elliptical function. The rotor thrust and electric power were measured, and the thrust coefficient and figure of merit was computed. The flow-field produced by the ducted rotors was measured in the near-field using laser Doppler velocimetry techniques. The inflow velocity approximately 3 mm upstream of the rotor blade leading edge was acquired and its significance on blade aerodynamics and performance is analyzed. Time-averaged contours of cross-stream vorticity reveal intense hub and blade tip vortex structures, which are impacted by the shape of the blade, particularly in the blade tip region. Tip vorticity as well as streamwise turbulence intensity and turbulent kinetic energy in this region were mitigated for the rotors with trapezoidal and elliptical blades. However, the turbulent structure of the jet produced by all three rotor blade shapes showed similarity at a mere 2.8 rotor diameters downstream of the rotor. This finding emphasizes the importance of blade design on the near-field dynamics of ducted rotor flows for aircraft propulsion.

First-Principles Simulation and Materials Screening for Spin-Orbit Torque in 2D van der Waals Heterostructures.

Recent advancements in spin-orbit torque (SOT) technology in two-dimensional van der Waals (2D vdW) materials have not only pushed spintronic devices to their atomic limits but have also unveiled unconventional torques and novel spin-switching mechanisms. The vast diversity of SOT observed in numerous 2D vdW materials necessitates a screening strategy to identify optimal materials for torque device performance. However, such a strategy has yet to be established. To address this critical issue, a combination of density functional theory and non-equilibrium Green's function is employed to calculate the SOT in various 2D vdW bilayer heterostructures. This leads to the discovery of three high SOT systems: WTe2/CrSe2, MoTe2/VS2, and NbSe2/CrSe2. Furthermore, a figure of merit that allows for rapid and efficient estimation of SOT is proposed, enabling high-throughput screening of optimal materials and devices for SOT applications in the future.

DFT aided comparative screening of mechanical, optoelectronic, and transport properties of double perovskites Cs2ScAuX6 (X = Cl, Br, and I) for green energy applications

A comprehensive comparative analysis has been performed to investigate the Cs2ScAuX6 (X = Cl, Br, and I) employing density functional theory. The WIEN2k code has been applied to optimize the structural arrangement of perovskites and calculate various aspects such as mechanical, optoelectronic, and transport characteristics. The results demonstrated that these perovskite compounds had both structural and chemical stability. The analyzed elastic characteristics of the Cs2ScAuX6 have shown that these compounds are mechanically stable, have anisotropy toughness, and provide durability against plastic deformation. The electronic characteristics are determined precisely and accurately using the Trans-Blaha-modified Becke-Johnson (TB-mBJ) potential. The compounds Cs2ScAuCl6, Cs2ScAuBr6, and Cs2ScAuI6 are semiconductors and have band gaps of 1.6, 1.5, and 1.05 eV, respectively, demonstrating an indirect nature. An investigation examines the optical characteristics within the energy range of 0–6 eV. The chosen materials reveal transparency in the lower energy spectrum of incoming photons and exhibit significant absorption and transmission of light. Therefore, it can be inferred that Cs2ScAuX6 materials possess optical properties that make them suitable for utilization in photovoltaic devices. Further, these materials elaborate substantial electrical conductivity, power factors, and figures of merit (ZT), making them efficient thermoelectric resources. At last, these results would be advantageous for experimental researchers and have also unveiled the substantial capability of these substances to be utilized in solar energy harvesting and thermoelectric devices.

CdZnTe semiconductor-based dual imager combining collimatorless and Compton imaging: Monte Carlo simulation

Compton imaging excels at visualizing gamma rays in the range of several hundred kiloelectronvolts to several megaelectronvolts. However, this technique has limitations in the imaging of low-energy gamma rays. In contrast, collimatorless imaging technique determines the location of a source by analyzing the distribution of interactions. Because the collimatorless imaging technique excels at imaging low-energy gamma rays that are easily shielded by detector components, it can compensate for the shortcomings of the Compton imaging technique. In this study, we propose a dual-mode imaging technique that selects the imaging method depending on the target gamma-ray energy and fuses them during reconstruction. The collimatorless imaging method demonstrated high angular resolution at low energy levels, whereas the Compton image surpasses it starting from 200 keV within its reconstructible range. The angular resolution of the dual-mode image was between those of the two methods. The trend of the positional error of gamma ray energy was similar to that of the angular resolution, and the dual-mode method exhibited the lowest average error of 0.7°. The dual imaging method exhibited higher efficiency, figure of merit, and signal-to-noise ratio by utilizing events from both imaging modalities. In addition, we investigated the geometrical effects of various structures.

Understanding the origin of the high thermoelectric figure of merit of Zintl-phase KCaBi.

Herein, we have investigated the unexplored thermoelectric properties of Zintl-phase KCaBi using first-principles calculation and the solution of the Boltzmann transport equation. KCaBi shows intrinsically very low lattice thermal conductivities (κl) along the (x(y), and z)-directions of (1.78, 0.68) and (1.15, 0.43) W m-1 K-1 at 300 and 800 K, respectively. Along with the effect of very low κl, the high figure of merit (ZT) for p-type KCaBi results from the high Seebeck coefficients (S) and optimal electrical conductivities (σ), which originate from the high and steep total density of state (TDOS) at the valence band edge and the less dispersed multi-valley nature of the valence band edge in the band structure. On the other hand, large ZT for n-type KCaBi results from moderate S and high σ caused by the sloped TDOS at the conduction band edge and the highly dispersed nature of the conduction band edge in the band structure, and very low values of κl. The highest ZT of KCaBi that we obtained at 800 K along the (x(y), and z)-directions was (1.83, 0.80) for the p-type case at a hole concentration of 1021 cm-3 and (1.36, 1.22) for the n-type case at electron concentration 7 × 1018 cm-3. Our study demonstrates that both p-type and n-type KCaBi have the potential to be promising thermoelectric materials.

Studies on a hadronic calorimeter with MPGD technology for a future Muon Collider experiment

In the context of the European strategy for particle physics, the Multi-TeV Muon Collider has emerged as a compelling alternative for advancing our understanding of the Standard Model, after the full exploitation of the High-Luminosity LHC. The physics programme at the Muon Collider includes precise measurements in the Higgs boson sector and the search for new physics at the TeV scale. Achieving these goals relies on accurate full event reconstruction, including the identification and precise four-momentum estimation of various particles. The Particle Flow (PF) algorithm is one of the most suitable approach for this task, exploiting information from tracking, calorimeter, and muon detectors for particle identification and measurements of their momenta/energies. Tracking detectors measure charged particle momenta, while calorimeters provide energy measurements for photons and neutral hadrons. Therefore, a combination of an exceptional tracking system and high-granularity calorimeters is necessary. However, one of the biggest challenges for a future experiment at the Muon Collider is to discriminate the product of the μμ collisions from the intense beam-induced-background (BIB), due to the unstable nature of muons, whose decay products interact with the detector material. To address this, an innovative hadronic calorimeter (HCAL) based on Micro Pattern Gas Detectors (MPGDs) is proposed. MPGDs offer robust technology for high radiation environments and a high granularity for precise spatial measurements. Dedicated studies are needed to assess and optimize the performance of an MPGD-based HCAL, including the development of medium-scale prototypes for performance measurements. The response of HCAL to incoming particles is examined through Monte Carlo simulations using Geant4, comparing the performance of digital and semi-digital readouts, with energy resolution as the figure of merit. The simulated geometry will be integrated into the Muon Collider software to study its impact on jet reconstruction within the full apparatus and in the presence of BIB. The simulation will be also validated through the test of a small-size calorimeter cell equipped with advanced resistive MPGD technologies, namely resistive MicroMegas, resistive μRWELL and RP-WELL.

An energy-efficient reconfigurable 18/12-bit 1 MS/s pipelined-SAR ADC

This paper presents a low-power 18/12-bit 1 MS/s reconfigurable pipelined-successive approximation register analog-to-digital converter (pipelined-SAR ADC). The proposed pipelined-SAR ADC employs a two-stage SAR structure coupled through a residual amplifier, with the forestage performing 12-bit coarse quantization and the poststage handling 7-bit fine quantization, one bit of redundancy is contained in the rear stage. The input signal is sampled by the first stage, SAR ADC, using the upper plate of a capacitor array and is quantized by charge redistribution. This eliminates the need of additional DACs and subtractors, allowing direct acquisition of the residuals. In addition, the residuals can be amplified by reusing the capacitor array as a switching capacitor. To minimize static power consumption, dynamic logic is adopted in each module of the pipelined-SAR ADC. The calibration of comparator offset and capacitor mismatch is carried out using analog front-end calibration techniques. Implemented in a 180 nm CMOS process, the simulation results show an extra-low power consumption of 1.76 mW with 3.3 V supply voltage and 1 MS/s sampling rate, indicating an exceptional Schreier figure of merit (FOMs) at 181.64 dB. By shutting down the modules of the second-stage SAR ADC, the 18-bit ADC can be dynamically configured as a 12-bit ADC with a sampling rate of up to 5 MS/s.

Magnetic-fluid-infiltrated bilaterally polished photonic crystal fiber with butterfly core for LSPR based magnetic field sensing via water based Fe3O4 magnetic fluid

In this manuscript, a sensor is devised employing photonic crystal fiber with localized surface plasmon resonance (PCF-LSPR), emphasizing the manipulation of refractive index (RI) through magnetic fluid (MF). The sensor's air holes adopt a hexagonal arrangement, forming a butterfly core design, and the transmission channels for the effective confinement of optical field energy relies significantly on the regions surrounding the central air hole in both directions.. MF serves as the sensing medium, and the top and bottom polished surfaces are coated with gold and titanium dioxide. The sensor undergoes analysis using the finite element method, scrutinizing its model characteristics, structural parameters, and sensing performance. The results indicate a wavelength sensitivity of up to 45,600 nm/RIU and a maximum figure of merit (FOM) of 434 RIU−1. Within the range of magnetic field 30–150 Oe, the highest magnetic field sensitivity records 3350 pm/Oe. Over the temperature range of 27.4–114 °C, the temperature sensitivity measures only 310 pm/°C. A maximum sensor resolution of 2.19×10−6RIU is achieved for x−pol. The linear relationship between the resonant wavelength and the magnetic field yields R2=0.9945, for degree (2) for x−pol. The proposed sensor exhibits notable advantages, including a structure which is very stable, high sensitivity, ease of integration, and resilience to electromagnetic interference. Additionally, it excels in detecting weak magnetic fields. Its potential applications span from industrial production, military technology, to medical equipment.

A pulse selection algorithm for SiPM-coupled CLYC detectors

SiPM-coupled Cs2LiYCl6:Ce3+ (CLYC) detectors are widely used for detecting neutrons and gamma rays in mixed radiation environments. Intensities and energies are obtained from the output pulses of the detector, including normal and anomalous pulses. Since anomalous pulses can negatively affect measurement accuracy, this study designs a pulse selection algorithm to improve them. This algorithm calculates the ratio of the mean to the standard deviation of an output pulse in a particular time window and categorizes it as normal or anomalous. The algorithm also uses the difference in ratio value between neutrons and gamma rays for pulse shape discrimination. In an experiment using a SiPM-coupled CLYC detector, 200,000 sets of pulses were obtained for 137Cs and Am-Be sources. The results indicate that this method can reject more than 94.2% of anomalous pulses, improving the energy resolution of 137Cs source from 8.9% @ 662 keV to 8.4% @ 662 keV. The figure-of-merit (FOM) of pulse shape discrimination is 1.23 for the Am-Be source, and this method can select specific pulse types based on the pulse-ratio value. In addition, the method is suitable for all pulse-mode detectors.

Study of mechanical, optoelectronic, and thermoelectric properties of Rb2ScAuZ6 (Z = Br, I) for energy harvesting applications

In the current article, the structural, mechanical, optoelectronic, and thermoelectric properties of Rb2ScAuZ6 (Z = Br, I) have been predicted using the density functional theory (DFT) approach. The tolerance factor, phonopy, and formation energy analysis validated the structural, dynamic, and thermodynamic stability of Rb2ScAuBr6 and Rb2ScAuI6, respectively. Likewise, the investigated elastic properties concluded that both materials exhibit mechanical stability and possess ductile characteristics. The directional-dependent elastic moduli revealed the anisotropy features. The indirect bandgaps determined by TB-mBJ approximation are 2.1 eV and 1.6 eV for Rb2ScAuBr6 and Rb2ScAuI6, respectively. Optical absorption, reflectivity, refractive index, and dielectric constants have been assessed in the energy range between 0 and 6 eV to ensure efficient absorption in the visible spectrum. Both materials have appropriate optical parameters for utilization in photovoltaic systems. Further, using the BoltzTraP code, the thermoelectric properties have been calculated to evaluate the thermoelectric efficiency. Both perovskites have lower lattice and electronic thermal conductivity, a higher Seebeck coefficient, and a higher figure of merit, making them ideal candidates for thermoelectric applications.

Double half Heusler (DHH) alloys with a high absorption coefficient shed light on the optoelectronic, thermoelectric, and structural, properties of X4Fe2Hf4Pt2 (X = Bi, Sb), derived from DFT data analysis

In this investigation, we employ density functional theory (DFT) with the generalised gradient approximation of Perdew–Burke–Ernzerhof (GGA-PBE) and the modified Beck-Johnson approach (mBJ-GGA). Our focus is on examining the optoelectronic and thermoelectric properties of Bi4Fe2Hf4Pt2 and Sb4Fe2Hf4Pt2 compounds. The findings indicate that both compounds are stable in non-magnetic phase (NM). Regarding electronic characteristics, it is revealed that these compounds are direct bandgap semiconductors. The optical analysis suggests that these compounds demonstrate high reflectivity within the visible and ultraviolet spectra, rendering them promising candidates for solar cells and photovoltaic applications. Furthermore, these materials present as highly promising candidates for thermoelectric purposes due to their remarkable figure of merit (ZT) and notable Seebeck coefficient (S) values. However, there is a lack of theoretical or experimental data available for these compounds for conducting comparison with our results. We think future experimenters attempting to synthesise these chemicals experimentally will benefit from the current study.