Group IV-VI Research Articles

Dynamical Symmetry-Reduction-Induced Giant Anharmonicity in IV-VI Compounds: Role of Cation Lone-Pair s Electrons.

The low thermal conductivity of group IV-VI semiconductors is often attributed to the soft phonons and giant anharmonicity observed in these materials. However, there is still no broad consensus on the fundamental origin of this giant anharmonic effect. Utilizing first-principles calculations and group symmetry analysis, we find that the cation lone-pairs s electrons in IV-VI materials cause a significant coupling between occupied cation s orbitals and unoccupied cation p orbitals due to the symmetry reduction when atoms vibrate away from their equilibrium positions under heating. This leads to an electronic energy gain, consequently flattening the potential energy surface and causing soft phonons and strong anharmonic effects. Our findings provide an intrinsic understanding of the low thermal conductivity in IV-VI compounds by connecting the anharmonicity with the dynamical electronic structures, and can also be extended to a large family of hybrid systems with lone-pair electrons, for promising thermoelectric applications and predictive designs.

Thermoelectric Transport Performance in p-Type AgSbTe2-Based Materials through Entropy Engineering.

Being a major obstacle, Ag2Te has always been restricted in p-type AgSbTe2-based materials to improve their thermoelectric performance. This work reveals a stabilized AgSbTe2 through Sn/Ge alloying as synthesized by melting, annealing, and hot press. Interestingly, addition of Sn/Ge in AgSbTe2 extended the solubility limit up to ∼30% and hence suppressed Ag2Te in Ag(1-x)SnxSb(1-y)GeyTe2 compounds and led to enhanced electrical transport. Moreover, electrical and thermal transport properties of AgSbTe2 have been greatly affected by the phase transition of Ag2Te near 425 K. However, high-entropy Ag0.85Sn0.15Sb0.85Ge0.15Te2 compound results in a stabilized rock-salt structure and presents a high power factor of ∼10.8 μW cm-1 K-2 at 757 K. Besides, density functional theory reveals that available multivalence bands in Sn/Ge-doped AgSbTe2 lead to reduction in energy offsets. Meanwhile, a variety of defects appear in the Ag0.85Sn0.15Sb0.85Ge0.15Te2 sample due to entropy change, and thus lattice thermal conductivity decreases. Ultimately, a high figure of merit of ∼1.5 is attained at 757 K. This work demonstrates a roadmap for other group IV-VI materials so that the high-entropy approach may inhibit the impurity phases with extended solubility limit and result in high thermoelectric performance.

Quantum-to-classical modeling of monolayer Ge2Se2 and its application in photovoltaic devices.

Since the discovery of graphene in 2004, the unique properties of two-dimensional materials have sparked intense research interest regarding their use as alternative materials in various photonic applications. Transition metal dichalcogenide monolayers have been proposed as transport layers in photovoltaic cells, but the promising characteristics of group IV-VI dichalcogenides are yet to be thoroughly investigated. This manuscript reports on monolayer Ge2Se2 (a group IV-VI dichalcogenide), its optoelectronic behavior, and its potential application in photovoltaics. When employed as a hole transport layer, the material fosters an astonishing device performance. We use ab initio modeling for the material prediction, while classical drift-diffusion drives the device simulations. Hybrid functionals calculate electronic and optical properties to maintain high accuracy. The structural stability has been verified using phonon spectra. The E-k dispersion reveals the investigated material's key electronic properties. The calculations reveal a direct bandgap of 1.12 eV for monolayer Ge2Se2. We further extract critical optical parameters using the Kubo-Greenwood formalism and Kramers-Kronig relations. A significantly large absorption coefficient and a high dielectric constant inspired the design of a monolayer Ge2Se2-based solar cell, exhibiting a high open circuit voltage of V oc = 1.11 V, a fill factor of 87.66%, and more than 28% power conversion efficiency at room temperature. Our findings advocate monolayer Ge2Se2 for various optoelectronic devices, including next-generation solar cells. The hybrid quantum-to-macroscopic methodology presented here applies to broader classes of 2D and 3D materials and structures, showing a path to the computational design of future photovoltaic materials.

Polarization Reversal of Group IV-VI Semiconductors with Pucker-Like Structure: Mechanism Dissecting and Function Demonstration.

Polarization imaging presents advantages in capturing spatial, spectral, and polarization information across various spectral bands. It can improve the perceptual ability of image sensors and has garnered more applications. Despite its potential, challenges persist in identifying band information and implementing image enhancement using polarization imaging. These challenges often necessitate integrating spectrometers or other components, resulting in increased complexities within image processing systems and hindering device miniaturization trends. Here, the characteristics of anisotropic absorption reversal are systematically elucidated in pucker-like group IV-VI semiconductors MX (M=Ge, Sn; X=S, Se) through theoretical predictions and experimental validations. Additionally, the fundamental mechanisms behind anisotropy reversal in different bands are also explored. The photodetector is constructed by utilizing MX as a light-absorbing layer, harnessing polarization-sensitive photoresponse for virtual imaging. The results indicate that the utilization of polarization reversal photodetectors holds advantages in achieving further multifunctional integration within the device structure while simplifying its configuration, including band information identification and image enhancement. This study provides a comprehensive analysis of polarization reversal mechanisms and presents a promising and reliable approach for achieving dual-band image band identification and image enhancement without additional auxiliary components.

Anti-Diabetic Effects of the 80% Methanolic Extract of Datura Stramonium Linn (Solanaceae) Leaves in Streptozotocin- Induced Diabetic Mice.

Managing diabetes mellitus with currently available drugs is costly, and the chances of side effects are high, leading to further studies for new and better medications from plant sources with the affordable and lower side effects. This study aimed to evaluate the anti-diabetic effects of Datura stramonium Linn (Solanaceae) Leaves Extract in Streptozotocin- Induced Diabetic Mice. Male Swiss albino mice were induced into diabetes using 150mg/kg of STZ. Mice were allocated randomly into six groups, five mice per group. Group I was a normal control, Group II was Diabetic negative control, group III was Diabetic positive control, Group IV-VI were Diabetic Mice that treated with extract (100, 200 and 400 mg/kg) for 14 days. The FBG measurements were done on 0, 7th, and 14th days of treatment. After 14th day of treatment the mice were anesthetized with diethyl ether. Then, blood was drawn by cardiac puncture to assess TC, TG, LDL-C, and HDL-C. The antioxidant activity of the extract was determined using a DPPH assay. The data were entered into Epi-Data version 4.6, exported to SPSS version 26.0, and analyzed using a one-way ANOVA followed by a Tukey post hoc test. P < 0.05 was considered statistically significant. The extract of D. stramonium reduced the FBG level by 19.71%, 30.27%, 40.95%, and 45.67%, respectively, for D. stramonium 100, 200, 400, and GLC 5 mg/kg on the 14th day of treatment. Diabetic mice treated with D. stramonium for 14 days showed a significant decrease in serum TC, LDL, and serum TG and a significant increase in body weight, and HDL level as compared to diabetic negative control. Antioxidant activities of the leaves extract were comparable to ascorbic acid with an IC50 of 172.79 μg/mL. These findings revealed that the D. stramonium leaves extract possesses significant Anti-diabetic activities.

Test the Effectiveness of Carrot Tuber Ethanol Extract Cream Preparation Formulation in Preventing Increased Melanin in Male Wistar Rats Exposed to UVB Light

This study was conducted with the aim of proving carrot tuber extract (Daucus carota L.) formulated in cream form can prevent an increase in the amount of melanin in the skin tissue of male wistar rats (Rattus norvegicus) exposed to UVB light and see histopathological changes due to carrot tuber extract given as a prevention of increasing the amount of melanin. This study is experimental with a post-test only control group research design. The test method used was testing the amount of melanin modified using a 13 watt Exoterra UVB 200 lamp. The animals tested were rats (Rattus norvegicus) male wistar strain aged 2-3 months, weighing ± 200 grams. Male rats were randomly divided into 6 groups. Each group consists of 5 male rats. The test area on the back of the back is 2x2 cm2. Group I male rats without cream administration as a negative control group, Group II male rats for Parasol Face Sunscreen Cream as a positive group. Group III is the group with the provision of basic ingredient cream and group IV-VI is the group with the administration of 25% carrot tuber extract cream; 50 %; 75 %. topically for 4 weeks.. The evaluation was performed by observing the amount of melanin at week 4 of histopathology analyzing in the test area. The results will be processed with IBM SPSS 21.0 and analyzed with the steps of Descriptive Analysis, Normality Analysis with data using Shapiro-Wilk test and Homogeneity using Levene's test, Comparative Analysis using one way Anova test, followed by Post-hoc test with LSD test. If the data is abnormal, use non-parametric analysis of the Kruskal-Wallis test followed by the Mann-Whitney test. The results showed that extra ethanol of carrot tubers can prevent the increase in the amount of melanin. This was shown by its ability to reduce melanin and histopathological changes in a group of male rats applied carrot tuber ethanol extract cream within 4 weeks

SnS2 as a Saturable Absorber for Mid-Infrared Q-Switched Er:SrF2 Laser.

Two-dimensional (2D) materials own unique band structures and excellent optoelectronic properties and have attracted wide attention in photonics. Tin disulfide (SnS2), a member of group IV-VI transition metal dichalcogenides (TMDs), possesses good environmental optimization, oxidation resistance, and thermal stability, making it more competitive in application. By using the intensity-dependent transmission experiment, the saturable absorption properties of the SnS2 nanosheet nearly at 3 μm waveband were characterized by a high modulation depth of 32.26%. Therefore, a few-layer SnS2 was used as a saturable absorber (SA) for a bulk Er:SrF2 laser to research its optical properties. When the average output power was 140 mW, the passively Q-switched laser achieved the shortest pulse width at 480 ns, the optimal single pulse energy at 3.78 µJ, and the highest peak power at 7.88 W. The results of the passively Q-switched laser revealed that few-layer SnS2 had an admirable non-linear optical response at near 3 μm mid-infrared solid-state laser.

An Ab Initio Study of Two Dimensional SnX2 and Janus SnXY (X = S, Se) Nanosheets as Potential Photocatalysts for Water Splitting

Discriminating appropriate two-dimensional (2D) photocatalysts for hydrogen generation is among the most prospective schemes to tackle with environmental contaminations. Unfortunately, the inferior capability to harvest solar light together with fast recombination of photoexcited carriers can severely reduce the catalytic ability with consequent limited commercial applications. In this work, a series of single-layer MXY (M = Ge, Sn; X, Y = S, Se, and Te) containing T- and H-phases about photocatalytic capabilities are systematically explored by first-principles calculations. First, the T- and H-MXY monolayers possess transformable band gaps of 0–2.37 and 0–1.49 eV, respectively. Astonishingly, the values of T-GeS2, T-SnS2, T-SnSe2, T-SnSSe, and H-SnS2 monolayers are higher than the threshold of redox potential difference (1.23 eV). Also, importantly, the carrier mobilities of anisotropic T-MXY monolayers can reach ∼1 × 104 cm2 V–1 s–1, which can rapidly transfer and accelerate the separation of the photoexcited carriers during photocatalytic reactions. Inspired by these significant benefits, the T-MXY monolayers have been built for photocatalytic water-splitting. Significantly, the driving force of photoexcited carriers in T-SnX2 and Janus T-SnSSe monolayers can greatly promote during the redox reactions. Furthermore, the hydrogen reduction and water oxidation reactions of T-SnX2 and T-SnXY monolayers can proceed spontaneously under irradiation. In addition, the few-layer and even monolayer T-SnS2 and T-SnSe2 have been experimentally synthesized in the literature. The potential photocatalysts of single-layer T-MXY have the 0.25–0.29 J m–2 cleavage energies, and ab initio molecular dynamics simulations further validate their stability. Our results provide support for 2D group-IV–VI chalcogenides for photocatalytic water splitting.

Electronic and optical properties of Janus-like hexagonal monolayer materials of group IV-VI

We report $ab\phantom{\rule{4pt}{0ex}}initio$ calculations of the electronic and optical response properties of Janus-like hexagonal monolayers materials of group IV-VI. By combining phonons spectra calculations and ab initio molecular dynamics simulations, we verify that some two-dimensional (2D) group IV-VI hexagonal materials are dynamically unstable. Our results of electronic band structure based on both density functional theory (DFT) with Heyd-Scuseria-Ernzerhof hybrid functional (HSE) and ${\mathrm{G}}_{0}{\mathrm{W}}_{0}$ formalisms indicate that the dynamically stable materials exhibit indirect band gaps. The calculations clearly reveal that the hexagonal crystal structure of the group IV-VI monolayers plays a crucial role not only in determining the width of the band gap but also on the electron-hole screening effect, and consequently the strength of the exciton binding energy. Despite their strong binding, exciton binding energies in these nanomaterials are found to be in agreement with a 2D Mott-Wannier model. We also show that most of the stable 2D materials exhibit strong optical absorbance in the visible range, being promising materials for ultra-thin-film photovoltaic applications. Thus, our systematic analysis on electronic and optical properties of hexagonal monolayer materials of group IV-VI will complement forthcoming experimental measurements and can pave the way for technological applications of those materials.

Syntheses of N2-bridged heterobimetallic complexes, their structural and qualitative bonding analyses

A series of N2-bridged (μ-η1:η1-N2) heterobimetallic complexes were prepared by the reaction of the dinitrogen complex [Mo(depe)2(N2)2] (depe = 1,2-bis(diethylphosphino)ethane) with the group IV-VI high valent metal halides [Cp2ZrCl2], NbCl5, TaCl5, MoCl5 and WCl4 via chloride substitution. Compounds [MoCl(depe)2(μ-N2)ZrCp2Cl] (1) and [MoCl(depe)2(μ-N2)M'Cl4(THF)] (2–5, M’ = Nb, Ta, Mo or W) were crystallized from the reaction mixtures. In the case of the reaction with WCl4, disproportionation of W(IV) was suspected but not evidenced. Single crystal X-ray diffraction analyses on all compounds allowed a systematic structural study, and the sketching of qualitative molecular orbital diagrams helped discussing the bonding situation and bolster the structural data.

Spin and Orbital Spectroscopy in the Absence of Coulomb Blockade in Lead Telluride Nanowire Quantum Dots

We investigate quantum dots in semiconductor PbTe nanowire devices. Due to the accessibility of ambipolar transport in PbTe, quantum dots can be occupied both with electrons and holes. Owing to a very large dielectric constant in PbTe of order 1000, we do not observe Coulomb blockade which typically obfuscates the orbital and spin spectra. We extract large and highly anisotropic effective Landé g-factors, in the range 20-44. The absence of Coulomb blockade allows direct readout, at zero source-drain bias, of spin-orbit hybridization energies of up to 600 \muμeV. These spin properties make PbTe nanowires, the recently synthesized members of group IV-VI materials family, attractive as a materials platform for quantum technology, such as spin and topological qubits.

Van der Waals imprinting of black-phosphorus-like binary alloyed monolayers with tunable band gaps and moiré superstructures

Fabrication of isostructural isovalent alloys is a powerful approach to discovering novel materials with emergent properties. This approach has been well established in traditional bulk materials, yet remains to be fully exploited in two-dimensional systems. Here we use black- phosphorus (BP)-like group-VA binary alloyed monolayers on BP-like group IV-VI substrates to demonstrate the enabling power of isomorphism and isovalency in fabricating two-dimensional alloyed monolayers with tunable properties. We achieve the formation of nearly freestanding BP-like ${\mathrm{Sb}}_{1\ensuremath{-}x}{\mathrm{Bi}}_{x} (0\ensuremath{\le}x\ensuremath{\le}1)$ monolayers on the GeSe substrate, with a semiconductor-to-metal transition and tunable moir\'e superstructures as $x$ increases. In contrast, BP-like ${\mathrm{Pb}}_{x}{\mathrm{Bi}}_{1\ensuremath{-}x}$ monolayers can be stabilized only for low Pb concentrations, and the contrasting behaviors are attributable to preservation or breakdown of isovalency in the two cases. This study establishes a generic approach to growing alloyed monolayers via van der Waals imprinting, opening a new avenue for materials discoveries with desirable functionalities.

Do two-dimensional group IV-VI M4X9 monolayers have photocatalytic activity toward overall water splitting? A comprehensive theoretical investigation

By means of first-principles calculations, we systematically evaluated the possibilities of M4X9s (M = Ge, Sn; X = S, Se, Te) as the platform for photocatalytic water splitting by checking their stabilities, electronic and optical properties, carrier properties, and the free energy changes of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). It was found that all the studied monolayers are stable. From the viewpoints of electronic and optical properties, the facts of suitable band gaps and band edge positions as well as good optical absorption meet with the fundamental requirements for a qualified photocatalyst toward overall water splitting. However, from the viewpoints of carrier mobility and carrier location, the electron mobilities are in moderate quantity whereas the hole mobilities are in single digits, and only Te-based materials have the feature of carrier separation, which are indicative of a low application prospect as the photocatalysts. Additionally, thermodynamic calculations clearly show that the external potential provided by the light-induced electrons and holes are insufficient to drive the HER and OER, respectively; thus, the M4X9s monolayers are not the ideal candidates for water splitting. Our results offer clear information and guidance of these novel M4X9s for the application in water splitting.

Valence fluctuation driven superconductivity in orthorhombic lead telluride

Chemical doping or elemental substitution and applying pressure are considered to be two effective tools to create superconductivity from a parent compound. The latter is more powerful than the former for contracting the lattice but does not bring about impurities, defects, or disorders compared with the former, thus serving as a good platform to examine or test any theoretical models for the born superconductivity. Among the various theories proposed for superconductivity, the electron-phonon interactions (or phonon mediated), spin fluctuations (or spin mediated), and valence fluctuations (or valence mediated) are the three major mechanisms. The first two have received extensive support from many elements and compounds over the last century, and only a few examples are believed to be a result of valence fluctuations. Lead telluride (PbTe), a Group IV-VI compound, is being examined as a promising candidate whose superconductivity is mediated by the valence fluctuations. The superconductivity has been reported in doped PbTe with the rocksalt NaCl structure at ambient pressure or parent PbTe with the body-centered cubic CsCl structure at high pressure. The pressure-driven intermediate orthorhombic phase in between has been known as a semiconductor with a large band gap and no expectation for the appearance of superconductivity. By doping I in the Te site to adding more carriers and partially substituting Pb by In with the expected valence change, however, we show that the co-doped PbTe exhibits superconductivity upon compression in the orthorhombic phase besides the expected one with the CsCl structure. Through the systematic studies of the structural, vibrational, electrical, and superconducting properties, we suggest that the observed superconductivity in the orthorhombic phase is mediated by the valence fluctuations associated with mixed valency on the In sites. This work thus not only offers an example for valence-mediated superconductivity but also fills the gap for the superconducting phase of PbTe in between the NaCl and CsCl structure.

Wide-spectrum polarization-sensitive and fast-response photodetector based on 2D group IV-VI semiconductor tin selenide

Tin selenide (SnSe) has attracted considerable interest recently on account of its low-symmetry lattice structure, great compatibility with key semiconductor technology, and remarkable electrical and optical performance. SnSe-based polarization-sensitive photodetectors show promising application prospects because of their fast response and excellent photoelectric performance. Here, an in-plane anisotropic SnSe nanosheet was synthesized and reported in detail by applying angle-resolved polarized Raman spectroscopy (ARPRS), polarization-resolved optical microscopy(PROM), angle-resolved optical absorption spectroscopy (AROAS), and other crystal structure characterization methods. Moreover, SnSe crystals exhibit superior polarization detection performance with a high anisotropic photocurrent ratio (2.31 at 1064 nm) due to the structure formed by the Van der Waals superposition of covalently bonded atomic layers. Furthermore, SnSe-based photodetectors have high responsivity (9.27 A/W), high detectivity (4.08 × 1010 Jones), and fast response (in the order of nanoseconds). These results suggest a new method for fabricating 2D fast-response polarization-sensitive photodetectors in the future.

Phase evolution during entropic stabilization of ZrC, NbC, HfC, and TiC

Multicomponent entropic ceramic solid solutions based on carbides of group IV-VI transition metals are of considerable scientific and practical interest due to their excellent physical and mechanical properties. An open question in this area is the formation of single-phase solid solutions from a mixture of metal carbides. Here we study the phase evolution of equimolar powder mixtures of HfC–ZrC–TiC, HfC–ZrC–NbC, and HfC–ZrC–TiC–NbC during pressure sintering in the temperature range from 1400 to 1900 °C. X-ray diffraction analysis showed that single-phase substitutional solid solutions (Hf,Zr,Ti)C, (Hf,Zr,Nb)C, and (Hf,Zr,Ti,Nb)C based on hafnium carbide are formed in several stages with the formation of simpler solid solutions with fewer components. A one-component state in an equimolar mixture of HfC–ZrC–NbC is formed at a temperature of 1500 °C, while in HfC–ZrC–TiC and HfC–ZrC–TiC–NbC it is formed at 1700 °C. The resulting ceramics based on (Hf,Zr,Ti,Nb)C multicomponent substitutional solid solution has better mechanical properties compared to (Hf,Zr,Ti)C and (Hf,Zr,Nb)C ternary ceramics: Young's modulus about 616 ± 77 GPa, hardness H = 36 ± 8 GPa, and fracture toughness 3.4 ± 0.5 MPa m1/2.

Mexican-hat dispersions and high carrier mobility of γ-SnX (X = O, S, Se, Te) single-layers: a first-principles investigation.

The shape of energy dispersions near the band-edges plays a decisive role in the transport properties, especially the carrier mobility, of semiconductors. In this work, we design and investigate the γ phase of tin monoxide and monochalcogenides γ-SnX (X = O, S, Se, and Te) through first-principles simulations. γ-SnX is found to be dynamically stable with phonon dispersions containing only positive phonon frequencies. Due to the hexagonal atomic lattice, the mechanical properties of γ-SnX single-layers are directionally isotropic and their elastic constants meet Born's criterion for mechanical stability. Our calculation results indicate that all four single-layers of γ-SnX are semiconductors with the Mexican-hat dispersions. The biaxial strain not only greatly changes the electronic structures of the γ-SnX single-layers, but also can cause a phase transition from semiconductor to metal. Meanwhile, the effects of an electric field on the electron states of γ-SnX single-layers are insignificant. γ-SnX structures have high electron mobility and their electron mobility is highly directional isotropic along the two transport directions x and y. The findings not only initially introduce the γ phase of group IV-VI compounds, but also serve as a premise for further studies on this material family with potential applications in the future, both theoretically and experimentally.

Epitaxial growth of black phosphorene enabled on black-phosphorene-like group IV-VI substrates

Black phosphorene (BlackP) is a promising two-dimensional material for next-generation nanoelectronics with a thickness-dependent bandgap and high carrier mobility. Yet to date, epitaxial growth of BlackP on a proper substrate remains a daunting challenge, which in turn prevents its mass production for device applications. Here we propose that BlackP-like group IV-VI substrates can be ideal candidates to promote epitaxial growth of BlackP. We first show, using first-principles approaches, that BlackP is energetically and thermodynamically stable on SnSe(001) as a representative substrate, which can be attributed to the isovalency nature and inherent structural similarity between the two. In contrast, as a close isomer of BlackP, blue phosphorene is thermodynamically unstable on SnSe(001). Next, we show that two phosphorus adatoms not only can readily form a dimer via P-P attraction, but such dimers also can diffuse isotropically and much faster than P monomers, both aspects highly desirable for initial growth and mass production of BlackP. Furthermore, BlackP grown on such semiconducting substrates can be directly exploited as a platform for novel optoelectronic devices, as demonstrated using the BlackP/SnSe heterobilayer that possesses a type-II band alignment and favors the formation of indirect excitons with desirable functionalities.

Amelioration of Cisplatin-Induced Kidney Injury by Pometia pinnata

Introduction: Cisplatin is one of the most effective anticancer drugs. But using cisplatin can cause very serious nephrotoxicity and acute kidney injury (AKI). Pometia pinnata (PE) or commonly referred to as matoa is a typical plant, especially Papua, Indonesia. Pometia pinnata belongs to the Sapindaceae family. This study aimed to determined the nephroprotective activity of the extract ethanol pometia pinnata on rats induced cisplatin. Methods: 30 rats are divided into six groups, each group were contained 5 rats. Group I was a normal group which rats only given CMC (carboxy methyl celluloce). Group II was a negative group which rats injected 7 mg / kgbw of Cisplatin in day 3. Group III was a positive group which rats given vitamin C 1% from day 1 to 7 and in day 3 rats were injected cisplatin. Group IV-VI were extract groups (100 mg / kgbb, 200 mg / kgb, 400 mg / kgbb) which rats orally given extract from day 1 to 7 and in day 3 rats were injected cisplatin. On day 8 rats were injected ketamine 1% which directly took the blood from the heart. Results: The result shows that EEPE on rats biochemical parameters including urea, creatinine, uric acid. Group II showed that there was a significant increase (p <0.05) compared to the normal group that was not given cisplatin and extracts. Whereas in the group given the extract in groups IV, V, and VI there was a reduction in biochemical parameters because the Pometia leaf extract had high antioxidant activity so that it had nephroprotective activity. extract ethanol pometia pinnata can reduced the level of sodium, potassium and chloride of each group after receiving cisplatin. Statistically group II that only given cisplatin has significantly different with group I (p<0,05) and also statically different with group VI (p<0,05).

Decoupling of the Electrical and Thermal Transports in Strongly Coupled Interlayer Materials.

Thermoelectric materials which enable heat-to-electricity conversion are fundamentally important for heat management in semiconductor devices. Achieving high thermoelectric performance requires blocking the thermal transport and maintaining the high electronic transport, but it is a challenge to satisfy both criteria simultaneously. We propose that tuning the interlayer distance can effectively modulate the electrical and thermal conductivities. We find group IV-VI and V semiconductors with a moderate interlayer distance can exhibit high thermoelectric performance. Taking SnSe as an example, we reveal that in the out-of-plane direction the delocalized pz orbitals combined with the relatively small interlayer distance lead to overlapping of the antibonding state wave functions, which is beneficial for high electronic transport. However, because of the breakdown of the chemical bond, the out-of-plane thermal conductivity is small. This study provides a strategy to enhance electrical conductivity without increasing thermal conductivity and thus sheds light on the design of thermoelectric devices.