The performance of inverted p-i-n type perovskite solar cells (IPSCs) is limited by non-radiative recombination caused by surface defects on the perovskite layer, which in turn leads to a loss of open-circuit voltage (VOC). In this study, a novel synergistic passivation strategy is proposed, which leverages the synergy between piperazine dihydriodide (PDI) and methylammonium iodide (MAI) to modify the perovskite/C60 interface in IPSCs effectively. This strategy fully utilizes the multiple structural and functional advantages of PDI. Its alkyl core-electron cloud-rich-NH terminal can effectively coordinate with deep-level defects, and the piperazine ring can interact with the FA+ ions, inhibiting their migration. Furthermore, MAI, due to its small molecular size, can penetrate the perovskite surface and repair iodine vacancies (VI). It also compensates for the deficiency of organic cations, achieving the ideal stoichiometric composition and enhancing interfacial contact. As a result, this synergistic strategy enhances energy level alignment, significantly suppresses non-radiative recombination at the perovskite/C60 interface, and improves carrier transport efficiency. The optimized PSC based on this strategy achieves a high VOC of 1.23 V (the theoretical limit for a 1.58 eV bandgap is 1.31 V, corresponding to a voltage deficit of only 0.08 V) and a PCE of 25.74%, and exhibits excellent long-term operational stability.

Electrocatalysts integrating high activity and exceptional chloride corrosion resistance are imperative for practical seawater electrolysis, yet their development remains profoundly challenging. Herein, Co/Mo dual-doped NiS nanoarchitecture (CoMo-NiS) has been constructed as efficient oxygen evolution reaction (OER) electrocatalyst for seawater electrolysis. The synergistic Co and Mo doping make nanoparticle-decorated nanoflakes with optimized electronic structure and abundant active sites. Consequently, the CoMo-NiS electrocatalyst achieves remarkably low overpotentials of 386 mV (alkaline freshwater) and 325 mV (alkaline seawater) at an industrial-grade current density of 1000 mA cm(- 2). The reconstructed hydr(oxy)oxides and sulfates establish a chloride-repellent surface layer via electrostatic interactions, enabling stable operation for >100 h at 100 mA cm- 2. Mechanistic studies through DFT calculations reveal that the synergy between Co doping and Mo-induced Ni vacancies reduces the energy barrier of the rate-determining step (*OH formation) and upshifts the d-band center. When integrated into a practical electrolyzer (Pt/C || CoMo-NiS), the system requires only 1.59 V to realize 100 mA cm- 2 and operates stably for at least 100 h, exhibiting great potential for sustainable hydrogen production from seawater.

The La0.7-xSr0.3NdxMnO3 ceramics (x=0.05-0.15) was prepared by the sol-gel method. The Rietveld refinement of the XRD patterns identified the single-phase rhombohedral perovskite structure (space group R-3c). The first-principles calculations, supported by X-ray photoelectron spectra (XPS), demonstrated an underlying competition mechanism. Although the increase of oxygen vacancies was enhanced by Nd3+ doping, the chemical pressure, which was dominated by this doping effect, led to the stabilization of the Mn4+ state. Due to the highly localized electrons of Nd3+, leading to a suppression of the Mn3+ /Mn4+ fraction. As a result, an enhanced suppression of Tc from 364 K to 344 K. A magnetic entropy variation of 5.01 J/(kg & sdot;K) was established with an application field of difference of 5 T at doping concentration of x=0.05. The critical exponents (x=0.05) reveal that the system follows the Mean Field theory and conforms to Widom's scaling hypothesis, offering a microscopic explanation for the improved magnetocaloric performance alongside the preservation of long-range magnetic ordering. This work presents a tug-of-war model in the Rare Earth doped manganite of a low-concentration Nd3+ doping (x approximate to 0.05) which provide a strategy of developing magnetocaloric materials.

A systematic evaluation of the optoelectronic properties of ferroelectric ternary oxides under strain is essential for their integration into functional devices. In this study, the R3-phase ternary oxide Zn3TeO6 was investigated using density functional theory to examine its stability, electronic structure, optical properties, ferroelectric behavior, and carrier mobility under both compressive and tensile strain. Calculations of elastic constants, molecular dynamics simulations, and phonon spectra confirm the stability of Zn3TeO6 within a modest strain range. Compressive strain increases phonon frequencies, elastic constants, and bandgap, while enhancing ferroelectric polarization. In contrast, tensile strain decreases the bandgap and promotes visible-light absorption. Carrier transport analysis reveals pronounced n-type conduction, with electron mobility reaching ∼150 cm2 V-1 s-1, further enhanced under compressive strain due to the suppression of polar optical phonon and piezoelectric scattering. These findings demonstrate that strain engineering offers an effective approach to tuning the multifunctional properties of R3-Zn3TeO6, highlighting its potential for ferroelectric and photovoltaic applications.

Two-dimensional (2D) van der Waals (vdW) ferroelectric heterostructures serve as an ideal platform for tunable optoelectronic devices, yet the precise regulation mechanism of interlayer coupling on their performance remains unclear. Here, a developed method to systematically investigate the interlayer coupling in CuInP2S6/AsSBr (CIPS/ASB) heterostructures based on first-principles calculations and theoretical calculations is proposed. The interlayer coupling constant K and interlayer coupling strength t are primarily driven by enhanced pz-orbital overlap, and the heterostructures with an S–S interface exhibit stronger coupling, K = ∼23 × 1019 N/m3 and t = ∼0.7 eV, than those with an S–Br interface, K = ∼15 × 1019 N/m3 and t = ∼0.5 eV. We find the tunable coupling by strain governs a spectrum of functional responses: it dictates band alignment transitions between type-I and type-II under strain at ∼4%, modulates interlayer vibrational modes at ultralow frequencies ∼28 cm−1, and switches semiconducting behavior between n-type and p-type to govern the electronic band structure and charge transfer dynamics of heterostructures. Crucially, optimized interlayer coupling in the CIPS(u)/ASB(d) configuration yields exceptional transport properties, achieving a hole mobility of 2990 cm2/V s. Consequently, power conversion efficiency is maximized at 9.25%, demonstrating that polarization- and stacking-engineered interlayer coupling provides a deterministic route to tailor optoelectronic performance. The calculations are consistent with the available evidence, implying that the proposed model could be a general approach to deal with interlayer coupling for designing high performance 2D vdW heterostructures.

Strain-engineered R 3-Zn 3 TeO 6 exhibits stable ferroelectricity, tunable bandgaps, enhanced visible-light absorption, and high n-type mobility, demonstrating its strong potential for multifunctional ferroelectric and photovoltaic device applications.

Ternary metal nitrides are of great interest in terms of their fundamental properties in recent years. Despite extensive experimental and computational explorations of these nitrides have been investigated, there are currently no reports of A3MN3 (A = Sr, Ba; M = Ga, In). Herein, comprehensive calculations are executed to study their crystal stability, optoelectronic features, and elastic properties. The results disclose that the thermodynamic stability of four compounds is ensured, and they are also dynamically and mechanically stable. Furthermore, Sr3MN3 and Ba3MN3 (M = Ga, In) are found to be brittle and ductile materials, respectively. All compounds are further predicted to be indirect-gap semiconductors with an energy gap of 1.0-1.5 eV. Besides, the observation of optical properties reveals their significant solar absorption. Notably, this research elucidates the potential of these nitrides for solar energy conversion.

Understanding the physical mechanism of interface transport properties that affect hydrogen production is key for improving the performance of photocatalytic hydrogen generation reaction in two-dimensional (2D) van der Waals ferroelectric heterostructures with various band arrangements. Herein, four CuInP2S6 (CIPS)/MoTe2 heterostructures with three band alignment transitions are obtained by controlling polarization direction and interface mismatch. To study the influence of polarization reversal and the different band alignments on transport properties, an analytical model is established to clarify the interface charge separation and recombination induced by built-in electric fields in type-II and Z-scheme heterostructures. The results show that polarization reversal can enhance the interface electron mobility by more than two orders of magnitude, and interface Auger recombination can greatly enhance the lifetime of photogenerated carriers at relatively higher bands. Moreover, by involving the energy loss induced by the interface electric field scattering rate and Auger recombination rate, we find that the solar-to-hydrogen efficiency of CIPS/MoTe2 with Z-scheme heterostructure is much larger than that of type-II heterostructures. Our prediction provides a quantitative approach to deal with the photocatalytic properties from interface transport under various band alignments and may offer guidance to pursue multifunctional applications in 2D ferroelectric materials.

This paper systematically investigates the influence of Ni2+ doping on the structural, morphological, and magnetocaloric properties of La0.8Sr0.2Mn1-xNixO3 (x = 0.05, 0.10, 0.15) ceramics using the sol-gel method and firstprinciples calculations. First-principles calculations reveal that Ni2+ doping alters the electronic structure and magnetic properties of the material, by altering the hybridization degree between the O-2p and Ni-3d orbitals, this change enhances the antiferromagnetic superexchange interactions and weakening the ferromagnetic double exchange interactions. The single-phase rhombohedral perovskite structure (R-3c space group (No.167)) of the material was confirmed by X-Ray Diffraction (XRD) and Transmission electron microscope (TEM). Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analyses further verify the successful incorporation of Ni2+ into the material, with elliptical particle morphology and uniform elemental distribution with no evidence of elemental segregation. Magnetic Property Measurement System (MPMS) measurements reveal significant changes in the magnetic entropy change (Delta SM) and relative cooling power (RCP) of La0.8Sr0.2Mn1-xNixO3 ceramics due to B-site Ni2+ doping. At a doping level of x = 0.05, the material exhibits a maximum magnetic entropy change of 4.02 J/(kg & sdot;K) under an applied magnetic field of 5 T, with a Curie temperature (Tc) close to room temperature (Tc = 294 K). This paper provides theoretical references and experimental evidence for the structural and magnetocaloric modifications in perovskite manganites induced by B-site doping.

Understanding charge behaviors at the interface of 2D van der Waals ferroelectric heterostructures is one of the important problems in fundamental physics and the key for designing high-performance optoelectronic devices. Herein, we develop an analytical model to study the interface charge separation and migration in CuInP2S6/AsSBr (CIPS/ASB) heterostructures. We reveal the influence of polarization reversal on the photovoltaic phenomenon using the tunable interface transport properties by modulating band alignment and built-in electric field. The results reveal that the interfacial electron mobility arises two orders of magnitude with the polarization reversal from up to down ward, which leads to the short circuit current and power conversion efficiency (PCE) enhanced by two times. Moreover, we find the thickness of CIPS and interface roughness play an important role in determining the optoelectronic properties as well, and suggest the optimal PCE can be obtained with ∼15 nm CIPS. Our method provides a general approach to deal with the optoelectronic properties and offers a guidance for improving the photovoltaic performances of ferroelectric-based nanodevices.

Ferroelectric semiconductors, with their inherent spontaneous polarization, present a promising approach for efficient charge separation, making them attractive for photovoltaic applications. The potential of β-AgGaO2, a polar ternary oxide with an orthorhombic Pna21 structure, as a light-absorbing material is evaluated. First-principles computational analysis reveals that β-AgGaO2 possesses an indirect bandgap of 2.1 eV and exhibits pronounced absorption within the visible spectral range. Optical simulations suggest that a 300 nm thick absorber layer could theoretically achieve a power conversion efficiency (PCE) of 20%. Device-level simulations using SCAPS-1D evaluate the influence of hole and electron transport layers on solar cell performance. Among the tested hole transport materials, Cu2FeSnS4 (CFTS) achieves the highest PCE of 14%, attributed to its optimized valence band alignment and reduced recombination losses. In contrast, no significant improvements were observed with the electron transport layers tested. These findings indicate the potential of β-AgGaO2 as a ferroelectric photovoltaic absorber and emphasize the importance of band alignment and interface engineering for optimizing device performance.

In recent years, researchers have been devoted to search for novel stable halide perovskite materials with outstanding photovoltaic performance. Herein, through density functional theory (DFT) calculations, we uncover for the first time the crystal stability, structural parameters, optoelectronic features, and photovolatic performance of Cs2HgPdI6. The Jahn-Teller-distorted Cs2HgPdI6 is detected by its structural feature. The stability of novel Cs2HgPdI6 is completely ensured by means of the DFT calculations. Accurate electronic structure calculations show that Cs2HgPdI6 exhibits an appropriate fundamental gap (1.278 eV). This band gap is mainly determined by the interaction between the I-5p and Pd-4d orbitals. Additionally, Cs2HgPdI6 has good carrier mobility and an ultra-low exciton binding energy. Meanwhile, it also exhibits relatively weak anisotropic optical properties and strong visible-light absorption. The large theoretical conversion efficiency of 31.7 % is illustrated for Cs2HgPdI6. Overall, our research highlights the great potential of this novel compound for photovoltaic applications.

A comparative investigation of electronic and transport properties of Te single atomic chain and Te single atomic chain encapsulated in carbon and boron nitride nanotubes (Te@CNT and Te@BNNT) based on first principle calculations. It is found Te@CNT and Te@BNNT show, respectively, type-II and type-I nanostructures with direct bandgap, and the band alignment relates to the diameter of NTs, whereas Te single atomic chain shows the transition between indirect and direct with compressive strain. Moreover, acoustic deformation potential (ADP) and ionized impurity (IMP) scattering rate play primarily responsible for the reduction of transport properties of Te single atomic chain and Te@NTs. The existence of NT can provide favorable surroundings to passivate dangling bonds and weak surface states for achieving high transport properties, and Te@CNT has the highest mobility due to the optimization of electronic and transport properties by CNT. Our results provide a guideline for designing high performance of 1D nanostructure for desirable applications.

The potential of novel ternary nitride ferroelectric semiconductors in photocatalysis has garnered significant attention. The stability, electronic structure, ferroelectric properties, and optical properties of Zn2NbN3, focusing on its potential for photocatalytic water splitting to produce hydrogen, are systematically investigated in this paper. First-principles calculations reveal that Zn2NbN3 meets mechanical stability criteria and exhibits excellent ferroelectric properties and ultraviolet light absorption. However, its large band gap limits visible light absorption. The calculated results indicate that phosphorus doping can reduce the band gap, significantly enhancing the visible light absorption coefficient. Additionally, P-doped Zn2NbN3 retains band edge positions suitable for hydrogen production and alters the valence band electronic distribution, improving light absorption and photocatalytic efficiency. In conclusion, phosphorus doping significantly enhances the photocatalytic performance of Zn2NbN3, making it a promising candidate for visible-light-driven hydrogen production and highlighting its potential in ferroelectric photocatalysis. This study provides a theoretical basis for developing efficient photocatalytic materials.

As renewable energy technologies advance, identifying efficient photocatalytic materials for water splitting to produce hydrogen has become an important research focus in materials science. This study presents a multi-task regression model (MTRM) designed to predict the conduction band minimum (CBM), valence band maximum (VBM), and solar-to-hydrogen efficiency (STH) of inorganic materials. Utilizing crystallographic and band gap data from over 15,000 materials in the SNUMAT database, machine-learning methods are applied to predict CBM and VBM, which are subsequently used as additional features to estimate STH. A deep neural network framework with a multi-branch, multi-task regression structure is employed to address the issue of error propagation in traditional cascading models by enabling feature sharing and joint optimization of the tasks. The calculated results show that, while traditional tree-based models perform well in single-task predictions, MTRM achieves superior performance in the multi-task setting, particularly for STH prediction, with an MSE of 0.0001 and an R2 of 0.8265, significantly outperforming cascading approaches. This research provides a new approach to predicting photocatalytic material performance and demonstrates the potential of multi-task learning in materials science.

Ferroelectric oxides with large band gaps or band edge positions that are difficult to cross the water oxidation-reduction potential are not conducive to photocatalytic hydrogen production. This study systematically investigates the potential application of R3c-structured InVO3 in the field of photocatalysis through density functional theory calculations. The mechanical and phonon frequency stability of InVO3 is verified through stability analysis, followed by the confirmation of its excellent ferroelectric properties through first-principles calculations. The calculated optical properties of InVO3 are explored to reveal its strong absorption of visible light and high photoelectric conversion efficiency. InVO3 exhibits excellent charge carrier transport properties through calculations of electron mobility, promising efficient energy conversion in photocatalytic water splitting. The band edge positions of InVO3 can cross the water oxidation-reduction potential, providing theoretical support for its application in the field of photocatalysis. R3c-structured InVO3 is a potential high-performance ferroelectric photocatalytic material.

Photocatalytic hydrogen production represents a sustainable and eco-friendly approach to energy generation. Employing Density Functional Theory (DFT) as the analytical framework, the study demonstrates that wurtzite-structured Zn2VN3 exhibits exceptional ferroelectric polarization, significantly surpassing that of conventional ferroelectric materials. Additionally, Zn2VN3 is characterized by enhanced carrier mobility, a critical attribute for augmenting photocatalytic efficiency. Of particular note is the advantageous alignment of Zn2VN3's band edge positions for visible light photocatalysis, coupled with a high solar-to-hydrogen (STH) efficiency, thereby positioning it as a formidable candidate for hydrogen production. The synthesis of a Zn2VN3@MoS2 heterojunction structure is shown to substantially enhance its photocatalytic properties, as evidenced by significant improvements in the hydrogen evolution reaction (HER) performance. Overall, this meticulous analysis positions Zn2VN3 as a material of considerable potential, poised to advance optoelectronic technology and contribute significantly to efficient and sustainable photocatalytic hydrogen production endeavors.

Traditional ferroelectric perovskite oxides are often limited by their wide band gaps, which restrict their efficient use of visible light. Pna21-LaWN3, an innovative perovskite nitride featuring a polar structure, has been investigated for its electronic structure, ferroelectric properties, and photovoltaic performance through Density Functional Theory (DFT) analysis. Our calculations reveal that Pna21-LaWN3 exhibits promising ferroelectric properties, primarily driven by the interaction between W and N atoms. Notably, Pna21-LaWN3 possesses a direct bandgap around 1.3 eV, coupled with a high absorption coefficient, making it highly efficient in absorbing visible light. SLME (Spectroscopic Limited Maximum Efficiency) analysis indicates that Pna21-LaWN3 can achieve significant short-circuit current, with a photoelectric conversion efficiency nearing 32%, thus emerging as an outstanding candidate for ferroelectric photovoltaic applications. The study underscores the potential of Pna21-LaWN3 in overcoming the limitations of traditional ferroelectric materials and paves the way for its use in high-efficiency solar energy harvesting.

Traditional ferroelectric perovskite oxides are often limited by their wide band gaps, which restrict their efficient use of visible light. Pna21-LaWN3, an innovative perovskite nitride featuring a polar structure, has been investigated for its electronic structure, ferroelectric properties, and photovoltaic performance through Density Functional Theory (DFT) analysis. Our calculations reveal that Pna21-LaWN3 exhibits promising ferroelectric properties, primarily driven by the interaction between W and N atoms. Notably, Pna21-LaWN3 possesses a direct bandgap around 1.3 eV, coupled with a high absorption coefficient, making it highly efficient in absorbing visible light. SLME (Spectroscopic Limited Maximum Efficiency) analysis indicates that Pna21-LaWN3 can achieve significant short-circuit current, with a photoelectric conversion efficiency nearing 32 %, thus emerging as an outstanding candidate for ferroelectric photovoltaic applications. The study underscores the potential of Pna21LaWN3 in overcoming the limitations of traditional ferroelectric materials and paves the way for its use in highefficiency solar energy harvesting.