High Absorption Peak Research Articles

The Energy Absorption Characteristics and Sound Absorption Behavior of In Situ Integrated Aluminum Lattice Structure Filled Tubes

Lattice structures, as integrated structure‐function engineering materials, have developed rapidly in industrial fields. In this study, the in situ integrated solid/hollow aluminum lattice structure filled tubes are designed and manufactured by a selective laser melting technique. The effects of structure parameters on compressive properties, energy absorption, and sound absorption are analyzed. The in situ integrated aluminum lattice structure filled tubes with hollow lattice structure and strengthened hollow lattice structure can achieve a wide adjustment of compressive property (31.04–185.64 MPa) and energy absorption density (11.21–51.70 MJ m−3) in a narrow density range. The compressive property and energy absorption are superior compared with ex situ aluminum lattice structure filled tubes due to the interaction and metallurgical bonding between the thin‐walled tubes and the aluminum lattice structures. The hollow structure design and altering its structure parameters can regulate the sound absorption coefficient and the corresponding peak frequency (the highest absorption peak is 0.723 at 2098 Hz). In addition, the hollow structure design can realize double absorption peaks (0.360 at 1462 Hz and 0.503 at 2122 Hz), presenting the potential for broadband sound absorption. Eventually, superior integrated energy/sound absorption structures can be obtained by the hollow structure design and its corresponding optimization.

Structural Modeling of Fluorinated Quinoxaline Core–Based Chromophores for Efficient Photovoltaic Materials: A DFT Study

ABSTRACTHerein, a series of fluorinated quinoxaline core–based chromophores (MTH1‐MTH6) with A1–π–A2–π–A1 configuration was designed by structural modulation of end‐capped acceptors in MTHR. The quantum chemical calculations were accomplished at MPW1PW91/6‐311G(d,p) functional to explore optoelectronic and photovoltaic properties of these designed compounds. The findings revealed that all the derivatives exhibited narrow band gap (Egap = 2.163–2.666 eV) with red shift spectra (610.24–766.944 eV in chloroform) as compared with MTHR. The designed compounds exhibited comparable open‐circuit voltage (Voc) and higher power conversion efficiencies (PCEs) as compared with the MTHR. Among the entitled chromophores, MTH1 was found to be a promising chromophore for organic solar cells (OSCs) owning to its lowest Egap (2.163 eV) with highest absorption peak (766.944 nm in chloroform and 717.709 nm in gaseous phase). The aforementioned findings indicate that molecular engineering of chromophores with extended acceptors enhances photovoltaic response, and this motivates researchers to develop highly effective photovoltaic devices.

Optimised structural, electronic, optical and mechanical properties of SrTiO3-xHx for photovoltaic applications: a DFT insight

Density Functional Theory (DFT) computations, by CASTEP code with GGA-PBE correlation functional, for SrTiO3-xHx have been carried out to compute elastic, mechanical, structural, electronic, and optical characteristics of SrTiO3-xHx perovskite hydride material at varied levels of replacements (x = 0, 0.3, 0.6, 0.9, 1.2, 1.5, 1.8, 2.1, 2.4, 2.7, and 3.0). With the doping of hydrogen, the structure changed from cubic to orthorhombic and then tetragonal. Elastic parameters and negative value of formation energies demonstrate the durability and formability of these materials. It is established that these compounds are brittle by examining the B/G ratio and Poisson ratio. A bandgap is increased from 1.791 eV to 2.441 eV as dopant concentration rises, changing the semiconductor's nature from indirect to direct. Additionally, a detailed explanation of the optical properties for photons in the energy spectrum of 0–10 eV was provided dielectric functions, refractive indices, extinction coefficients, and 0–50 eV were provided including reflectance, absorbance, and energy loss. By increasing hydrogen doping, the highest absorption peak in the visible region is observed for x = 2.1, which shows that SrTiO3-xHx perovskite hydride has revealed stronger potential for photovoltaic applications.

Effect of silver nanoparticles synthesized by Lecanicillium lecanii and their combinations with insecticides (Sivanto and Deltamethrin) on larvae and adults of Tribolium confusum Duv. (Tenebrionidae : Coleoptera)

This research focused on developing a nanopesticide derived from silver nanoparticles (AgNPs) synthesized through the metabolic activities of the fungus Lecanicillium lecanii Gams & Zare 2001). The study aimed to assess its efficacy against the flour beetle Tribolium confusum and explore its synergistic effects with two chemical pesticides, Sivanto 20% and deltamethrin 2.5%. Biotinylated AgNPs were successfully produced using the biomass of the fungus L. lecanii. Characterization of silver nanoparticles was achieved through the observable color change of silver nitrate solution (AgNO₃) from a clear or watery state to red, brown, or dark red, confirmed by UVV is spectroscopy, with the highest absorption peak at 420 nm, indicative of silver element absorption. Transmission electron microscope images illustrated that the biologically prepared AgNPs with L. lecanii exhibited spherical shapes with sizes ranging from 12 to 40 nanometers. Various concentrations of nanopesticide, Sivanto, and deltamethrin were tested for the treatment of grains. A concentration of 1 ml/L of deltamethrin showed superior performance, with the mortality ratio increasing with prolonged exposure. Both Sivanto and deltamethrin (0.5 ml/L and 0.4 ml/L) caused 100% mortality, followed by the nanopesticide (30% concentration), reaching a corrected mortality rate of 39.3% against adults of T. confusum. In the larval experiment, the mortality rate was high when applying AgNPs at a concentration of 100%, comparable to Sivanto 0.5 ml/L under similar conditions. Deltamethrin exhibited complete mortality at a 1 ml/L concentration. [ Keywords: Silver Nanoparticles, Lecanicillium lecanii, Tribolium confusum

CrI3/Arsenene vdW heterstructure: Outstanding physical properties and substantially enhanced magnetic stability

CrI3 monolayer has attracted much attention, but it holds a very low magnetic stability, with Curie temperature (TC) of 45 K, seriously limiting the practical applications. To find solutions for this issue, we construct CrI3/As vdW heterstructures (vdWHs). Calculations show that such vdWHs are half-semiconductor with excellent mechanical property and TC of 75.9 K, improved by 73.3 % compared with CrI3 monolayer. Due to a weak orbital hybridization and coupling occurring between As layer and Iin atom-layer upon vdW interactions, the potential well of interfacial Iin atom-layer would become shallower, which make electron flow out from Iin atoms and magnetic moments increased for Cr and Iin atoms, in turn, the ferromagnetic (FM) coupling in Cr-Iin-Cr superexchange magnetic coupling channel is strengthened. Particularly, the magnetic stability can be significantly raised by compression strain, leading TC up to 111.3 K, which is caused by super-exchange interactions of both Cr-Iin-Cr and Cr-As-Cr channels, and magnetic proximity effects increased further. For light absorption, the red-shifted absorption edge relative to CrI3 monolayer and high absorption peak appearing in visible and infrared region allow heterstructures absorbing solar energy in a wider range. Such a phenomenon can be further strengthened by compression strain.

Effective photoabsorption and band-structural engineering in CuxO/NiO interfacial photosensor for improved ultraviolet response

Energy bands modulations in thin films heterostructure has offered exceptional leads towards the development of photosensing material. In this work, nanostructured metal oxides interfacial electrode structure has been employed to fabricate a highly sensitive ultraviolet (UV) sensor with high responsivity and detectivity. A unique, simple and cost-effective electrodeposition approach was adopted for the growth of the film samples. The interfacial structural effect and optical energy band modulations on the photo-electronic structure and UV detector performance of the structure have been examined. The films had fair transmissions of the visible light spectrum with CuxO dominance in the resulting bilayer structure and a high absorption peak in the ultraviolet (UV) region. The energy band gap redshifted towards the bilayer structure from 3.74 to 2.67 eV. Charge carriers trapping through surface recombination has been found to reduce from the assistance of ohmic contact formation of the heterostructure. The bilayer film-based photodetector demonstrated enhanced performance with photodetectivity (1.6⨯1011 Jones at 0.068 mWcm−2 power density), attributable to the existence of lower recombination state in the structure, according to the UV sensing study. The study showed that tailoring dissimilar metal oxide semiconducting films to the bilayer (CuxO/NiO) structure can provide excellent UV photodetector performance over single-layer of NiO and CuxO.

Synthesis and characterization of gold/nickel oxide nanoalloy via green laser irradiation

In the present study, a gold/nickel oxide (Au/NiO) nanoalloy was generated by irradiating two nano-metallic material solutions using a green laser. The produced Au/NiO nanocomposites were characterized by UV–Vis–NIR spectroscopy, an X-ray diffraction pattern, TEM and SEM imaging, and photoluminescence and DLS tests. Depending on the concentration of Au NPs in the suspension medium, the final characteristics of Au/NiO nanocomposites vary significantly. Au NPs exhibit an extremely high plasmonic absorption peak at approximately 530 nm. They melted by absorbing the energy of the second harmonic of the laser beam, forming an Au/NiO nanocomposite. Additionally, our results demonstrated that after irradiation with a green laser, the bandgap energy of samples was reduced to 5, 4.3, and 4 eV as the number of Au NPs in nanocomposite structures increased, indicating that the addition of gold to nickel oxide NPs improves their conductivity and reduces the bandgap energy of samples. Moreover, due to composition formation, the number and size of Au NPs dropped following green laser irradiation, while NiO NPs grew in size. This work created an AuNiO nanocomposite by laser ablation, which is a highly effective approach for fabricating nanostructures.

Green Synthesis of Iron Nanoparticle, their Characterization Using Melia Azedrach Leaves Extract and its Phytochemical Analysis

The research aimed to create eco-friendly, affordable, and stable Iron Nanoparticles using Melia Azedarach plant extract and FeCl3 salt. The process involved extracting methanol, creating a solution, and combining it with FeCl3 salt. The nanoparticles were analyzed using FT-IR and UV-Vis spectroscopy. The study confirmed the synthesis of nanoparticles through visual examination and UV-Vis analysis, revealing a color shift from green to dark brownish-blackish and a high absorption peak at 430nm.FT-IR data showed a peak in iron nanoparticle samples, indicating O-H stretching in the phenolic group and C=O stretching in the carbonyl group. Phytochemical results showed cardiac glycoside, flavonoids, and steroids in Melia Azedarach plant extract. This research concluded that the Melia Azedarach plant leaf extract has the potential to create easy, affordable, environmentally stable, and biocompatible iron oxide nanoparticles.

Simultaneous effect of medicinal plants as natural photosensitizers and low-level laser on photodynamic inactivation.

Photodynamic inactivation (PDI) technology is a promising alternative to antibiotics. This technology is defined as the inhibition of bacterial growth with photosensitizers while irradiated with low-level laser light in the wavelength of 532 ± 2.08nm. A challenging area in this field is selecting photosensitizers with antibacterial potential. In this paper, to enhance the antibacterial efficiency, the photosensitizers (the selected plant extracts) with a high absorption peak at the selected laser frequency, 532nm, were prepared. Low-concentration ethanolic plant extracts of Hibiscus sabdariffa and Opuntia ficus-indica were found to exhibit significant antibacterial activity against, Acinetobacter baumannii ATCC 19606 and, Staphylococcus aureus ATCC 33591 as two important human pathogenic bacteria. The effectiveness of these natural photosensitizers was measured by determining their Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values and by performing a time-killing assay in the absence and the presence of laser irradiation. Our results showed that the combination of low-level laser irradiation and the selected photosensitizers had excellent potential for treating in vitro bacterial infections. Therefore, PDI technology has great potential as a viable alternative to traditional antibiotics for combating bacterial infections. This study presents a promising avenue for further exploration of PDI and the use of laser technology in medical science.

Computational analysis of AlXSnSe4 (X = Ag and Cu) quaternary compounds: Uncovering first-principles insights into electronic structure, optical, and thermoelectric nature

Employing the recognized density functional theory, here we studied the multifaceted interactions of the structural, electrical, optical, and transport nature of new direct band gap AlXSnSe4 (X = Ag and Cu) quaternary materials. Significant band overlap between the electronic states of Tot-Ag and Tot-Se suggests that these two systems have strong bonding properties. The minima and maxima of the conduction band and valence band are located at the high symmetry Gamma-point in the first Brillouin zone which suggests a good behavior for optoelectronic devices. There exists a clear correlation between the dipole inter-band transition probability and the value of the real component of the dielectric constant. The highest absorption peaks are found in the ultraviolet spectrum, indicating that these materials are effective absorbers of the low- and medium-UV radiation. The high reflectivity values for both materials varied between 4.0 eV and 13.5 eV as photon energy increased. The considered materials are also suitable to be used in thermoelectric applications, that is confirmed from their significant and notable thermoelectric features.

The SnC/WS2 vdW heterojunction: A prospective direct Z-scheme photocatalyst for overall water decomposition with high STH efficiency and catalytic activity

Searching for an advanced photocatalyst is a solution to the global energy scarcity and environmental problem. In this paper, we construct a SnC/WS2 heterojunction and its structural, electronic, optical and photocatalytic properties have been investigated by first-principles calculations. The SnC/WS2 heterojunction exhibits thermodynamic stability, with a type II (staggered) energy band structure and an indirect bandgap of 1.393 eV. A built-in electrical field with direction from SnC layer to WS2 layer is formed together with a band bending in interface region. The SnC/WS2 heterojunction is a direct Z-scheme photocatalyst supporting overall water decomposition, allowing a reductive reaction to take place in the conduction band of the SnC layer to produce H2 and an oxidative reaction in the valence band of the WS2 layer to produce O2. Meanwhile, the light absorption of the SnC/WS2 heterojunction is superior to that of the two single layer materials, with the highest absorption peak 5.3 × 105 in visible light region and a solar-to-hydrogen efficiency of 42 %. Furthermore, the Gibbs free energy calculations demonstrate the high catalytic activity of the SnC/WS2 heterojunction for redox reactions. The findings reveal that the SnC/WS2 heterojunction is a super-efficient direct Z-scheme photocatalyst for overall water splitting.

Transient liquid phase bonding of Sn-Pb solder with added Cu particles

In this paper, the 1%-20% Cu particles were uniformly distributed in SnPb solder by mechanical mixing method to prepare composite solder. The solder was welded by eutectic welding and the high temperature failure test was carried out. The melting point and internal structure of solder were observed before reflow, after welding and after aging, and the existence of high-temperature resistant skeleton was found. It could be seen from the DSC curve that the solder absorption peak changes in a step-like manner, and the proportion of the high melting point absorption peak gradually increases with the aging process. The micro-structure of solder joints showed that a thin layer of IMC was formed around the Cu particles in the solder joints after welding, and the IMC in the solder joints had grown continuously until they contacted each other and formed a skeleton structure with aging. The skeleton structure improved the high temperature resistance of the solder joint. EDS analysis showed that the distribution of Cu element in the solder was similar to that of Sn, and the Pb element was enriched. The distribution of metal elements indicates that the solder joint was mainly composed of Cu6Sn5 IMC skeleton and Pb rich phase, and the solder component phase was high melting point component transformation.

Pressure induced variations from semiconducting to metallic for halide perovskite NaBeCl3 by first-principle calculations

By the first-principles, the mechanical, electronic, and optical properties of NaBeCl3 cubic crystal at 0 ∼ 200 GPa are systematically researched for the first time. The lattice constant of NaBeCl3 is 4.55 Å. According to Cauchy's pressure, B/G and Poisson's ratio, NaBeCl3 exhibits excellent ductility under various pressures. The Poisson's ratio indicates the bonding type of NaBeCl3 is ionic. The electronic properties suggest that NaBeCl3 is an indirect semiconductor with a visible band gap of 2.314 eV at 0 GPa. Its band gap always narrows as pressure increases from 0 to 120 GPa. And NaBeCl3 demonstrates semimetal behavior at 120 GPa. When the pressure exceeds 120 GPa, NaBeCl3 exhibits metallic behavior. Additionally, the results of optical properties show that the wide range of absorbed energy, high absorption peak, and high peak of dielectric function at high pressure make NaBeCl3 potential for optoelectronic devices. The research in this paper would contribute to the theoretical guidance for future experimental studies of the NaBeCl3 crystal.

Green preparation of silver nanoparticles using leaf extract of Amoora rohituka for antioxidant, antibacterial and anticancer applications

Metal nanoparticles made from biological source are currently catching a lot of attention to the researcher because of their versatile application in different fields. Realizing this fact, the present study describe the utilization of Amoora rohituka leaves to prepare silver nanoparticles (AgNPs) and make their characterization along with evaluating bioactivities using different techniques. In UV–Vis spectrum, the highest absorption peak at 446 nm confirmed the formation of AgNPs whereas the FTIR spectrum exposed the participation of phytoconstituents with different functional group that play as reducing and capping agents in AgNPs synthesis. The face centered cubic structure with crystalline nature was found for AgNPs in XRD analysis and SEM captured the spherical-shaped images of nanoparticles with diameter ranging 5.63–23.6 nm. In antioxidant assay, the synthesized AgNPs exhibited prominent free radical scavenging capability for DPPH (IC50: 35.34 μg/mL) and ABTS∙+ (IC50: 10.39 μg/mL) radicals. The antibacterial efficiency of AgNPs can be ranked as Shigella boydii > Staphylococcus aureus > Escherichia coli. Moreover, the AgNPs displayed cytotoxicity against EAC cells in a dose-dependent pattern (IC50: 15.84 ± 0.85 μg/mL). The overall findings help to conclude that this green manufactured AgNPs might be a promising candidate for many biomedical applications.

IR-775 - Hyptis loaded bioactive nanoparticles for enhanced phyto-photothermal therapy of breast cancer cells

Photo-responsive therapy is an emerging treatment modality due to its bioimaging and therapeutic properties. Phototherapy induces localized hyperthermia and selectively eradicates cancer cells. The current study showed that multifunctional biodegradable liposome nanosystem (HIL NPs) containing Hyptis suaveolens bioactive molecules and IR-775, a NIR dye showed efficient bioavailability to cancer ells and allowed tumor ablation upon NIR laser irradiation. The resulting entities present in the nanosystem, i.e., bioactive molecules of Hyptis, serve as an anticancer agent, and IR-775 helps in the photothermal ablation of highly metastatic breast cancer cells. Hyptis suaveolens is a weed that grows rampantly, impeding the growth of neighboring plants; nonetheless, its bioactive compounds have demonstrated therapeutic benefits. The obtained HIL NPs, photothermally active liposome nanosystem showed a high fluorescence absorption peak in the NIR range and delivered a photothermal conversion efficiency of 55.20 % upon NIR laser irradiation. TEM and particle size analyzer revealed that HIL NPs have a size of 141 ± 30 nm with a spherical shape. The results of in-ovo (zebrafish) experiments have shown efficient bioimaging capabilities with minimal concentrations of HIL NPs compared to respective controls. Furthermore, in-vitro studies of HIL NPs against triple-negative breast cancer (4T1) indicated effective anticancer activity by a combined cytotoxic effect and hyperthermia. Tumor ablation was facilitated by reactive oxygen species production and hyperthermia, leading to DNA damage and apoptosis due to overexpression of ɣ-H2AX, Cathepsin B, and p53, which halted cancer cell proliferation. Therefore, HIL NPs demonstrated effective anticancer effects induced by combined phyto-photothermal therapy when evaluated against an in-vitro breast cancer model.

Sound-absorption and mechanical properties of multisheet Gyroid lattice structures by stereolithography

Sound-absorbing materials with high load-bearing capacities are particularly important in many engineering applications. However, the low load-bearing capacity of conventional sound-absorbing materials limits their engineering applications. In this study, a multisheet parallel design concept is employed to design multisheet sound-absorbing and load-bearing lattice structures. Results show that the multisheet structure outperform the single-sheet lattice structure. The former exhibits a maximum absorption coefficient of 1, a 1x increase in the maximum average absorption coefficient, and a 127x increase in the maximum frequency compared with the latter. Under compression, the multisheet structure exhibits elastic modulus and yield strength values that are 0.43 and 0.52 times those of the single-sheet structure, respectively. Compared with different sound-absorbing structures, the multisheet structure exhibits remarkably high peak absorption coefficients and significant sound-absorbing performance advantages in specific frequency bands. This study presents a new design approach for creating multifunctional structures with sound-absorbing and load-bearing capabilities.

Computation of the Dielectric and Optical Properties of Dimethylammonium Tin Triiodostanate (II) Perovskite for Solar Cell Application

Hybrid halide perovskites are promising photovoltaic materials for use in solar cells. The ongoing research on perovskites have shown that these materials are potential light-harvesting mediums. The optical properties of dimethylammonium triiodostanate (II) (DASnI3) a hybrid halide perovskites needs to be studied because it can be a good light absorber material due to the wide band gap exhibited. The real and the imaginary parts of the dielectric is a measure of the extent of light absorption. The GGA+U exchange-correlation implemented in Quantum ESPRESSO was used basing on density functional theory to obtain the optical properties. The DASnI3 has a direct band gap of 2.7 eV with the real part of the dielectric diagram indicating that the maximum value of ε1 (ω) is in the visible range of (3.0–3.5 eV). High absorption peaks were also observed in the visible spectral region at energy of around (3.5–4.5 eV) with several weak peaks observed in the energy range of (4.5–14.0 eV). The band structure and the dielectric functions are important in the study of optical properties. These properties expresses the interaction of light with the material medium and thus the luminescence of the device which are important in the use of DASnI3 as a solar cell material in photovoltaics.

Electronic structure and optical absorption property of BaTiO3/BiCoO3

In this paper, we calculated the different forms of BaTiO3/BiCoO3 composite structure, predicting their visible light absorption performance based on the electronic structure using the first principles calculations. Firstly, six possible compounds that come from BaTiO3 and BiCoO3 were constructed. By calculating the different antiferromagnetic (AFM) structures of strip, columnar, and layered composite structures, it is found that the ground state of the composite structure changes to G‐type AFM structure from C‐type AFM structure of pure BiCoO3 under the influence of BaTiO3. Energy band calculations show that band gaps of three composite structures are smaller than those of pure BaTiO3 and pure BiCoO3. Furthermore, density of states analysis shows that the conduction band minimum (CBM) and valence band maximum (VBM) of three composite structures are mainly from the contribution of Co 3d and O 2p. For the characteristic that CBM and VBM of materials come from different atoms, it would reduce the recombination opportunities of electrons and holes and is conducive to the increase of photoelectric conversion efficiency under visible light irradiation. The calculation of optical properties shows that optical absorption coefficients of three composite structures are much larger than that of BaTiO3, especially the layered composite structure. There is a high absorption peak near 500 nm of the solar spectral irradiation maximum, which is significantly important to improve the optical energy conversion efficiency of the composite materials. The work provides an effective way for the application of wide band gap ferroelectric materials in ferroelectric photovoltaic.

Colourimetric Method for Assaying Tetracycline Hydrochloride in Pharmaceutical Formulations via Zirconium Complex Formation

This paper includes development of a sensitive, accurate and precise direct spectrophotometric approach to estimate tetracycline hydrochloride in the bulk solution and in its pharmaceutical preparations. The method was based on the reaction of tetracycline hydrochloride with zirconium (IV) in presence of acetate buffer solution at pH3.6 to form a yellow complex with a highest absorption peak at 398 nm. The resulting complex conforms Beer's law to cover the concentration in the range of 0.5 to 12.5 µg/ml with a good determination coefficient (r2 =0.9989), molar absorptivity of 2.7798×104 l/mol.cm and Sandell's sensitivity of 0.0173 μg/cm2 . The Limits of detection (LOD) and quantitation (LOQ) were equal to 0.019 and 0.063μg/ml, respectively. A relative standard deviation (precision) was evaluated to be better than 0.91% depending on the concentration levels, whereas the value of recovery percentage were in the range of 97.20% to 103.82%. The approach was useful to the analysis of tetracycline hydrochloride in capsules and skin ointment. The statistic factors t-test and F-test values have also been investigated and revealed that the experimental "t" and "F" results were less than the theoretical results at confidence level of 95%

A DFT computational design and exploration of direct band gap silver-thallium double perovskites

Researchers have addressed the non-traditional power generation schemes, as alternatives to the traditional fossil-fuel methods enormously, since the scientific community has serious concerns about shortages of energy on our planet for future generations. In this scenario, innovative materials for photovoltaic and thermoelectric device applications are required by addressing current issues of instability and efficiency. Perovskites are very popular in this regard particularly having higher power conversion efficiency of 25.2% in the case of solar cells. In the current article, we investigated innovative small direct band gap double perovskites (elapsolite) Cs2AgTlX6 (X = Cl, Br) with a comprehensive discussion on structural, electronic, optical, and thermoelectric properties using a first-principles approach. The compounds under investigation are found stable, efficient, and economical with alluring optical and thermoelectric properties. The higher absorption peaks in the visible range, substantial optical conductivities (∼1016sec-1), and a lower percentage of reflection in the visible range makes these compounds fascinating for solar cell applications. Whereas large values of Seebeck coefficients, electrical conductivities, the figure of merits (greater than unity), and small values of thermal conductivities suggest the applications of these compounds in thermoelectric generators.