Search

The self-rectifying memristor (SRM) is a promising device prototype for high-density three-dimensional (3D) integration and high-efficiency in-memory computing (IMC) by virtue of its ability to effectively suppress sneak current, simple device structure, and low energy consumption. Theoretically understanding the intrinsic mechanisms of SRM is a matter of concern. Here, we fabricated a Ta/TaOx/HfO2/Pt-stacked SRM exhibiting >103 on/off ratio, rectification ratio, and nonlinearity. The SRM can be repeatedly programmed by more than 106 pulses and demonstrates robust retention and high scalability (∼59 Mbit). A reasonable interface model for this SRM is established based on first-principles calculations. Using self-energy corrected density function theory, we calculate the barrier heights at each interface. Detailed I–V curve fitting and energy band analysis are performed and computationally verified to explain the intrinsic reasons for resistive switching, self-rectifying, and nonlinear behaviors. The work may advance the development of SRM prototype to enable energy-efficient 3D IMC. [ABSTRACT FROM AUTHOR]

Spin filtering is a fundamental operation in spintronics, enabling the generation and detection of spin-polarized carriers. Here, we proposed and theoretically demonstrated that a 3d transition metal (TM) doped hydrogenated silicon quantum dot (TM:H-SiQD) is a suitable candidate for spin-filter devices. Using density functional theory, we investigate the structure, electronic properties, and magnetic behavior of TM:H-SiQD. Our calculations demonstrate that Mn:H-SiQD exhibits the highest stability. The designed spin-filter device using Mn:H-SiQD shows a spin-filtering efficiency of 99.9% at 300 K electrode temperature along with very high conductance. This remarkable efficiency positions it as a promising candidate for spintronic devices. [ABSTRACT FROM AUTHOR]

The ferroelectric tunnel junction (FTJ), which possesses a simple structure, low power consumption, high operation speed, and nondestructive reading, has attracted great attention for the application of next-generation nonvolatile memory. The complementary metal–oxide–semiconductor-compatible hafnium oxide (HfO2) ferroelectric thin film found in the recent decade is promising for the scalability and industrialization of FTJs. However, the electric performance, such as the tunneling electroresistance (TER) effect, of the current HfO2-based FTJs is not very satisfactory. In this work, we propose a type of high-performance HfO2-based FTJ by utilizing a ferroelectric/dielectric composite barrier strategy. Using density functional theory calculations, we study the electronic and transport properties of the designed Ni/HfO2/MgS/Ni (001) FTJ and demonstrate that the introduction of an ultra-thin non-polar MgS layer facilitates the ferroelectric control of effective potential barrier thickness and leads to a significant TER effect. The OFF/ON resistance ratio of the designed FTJ is found to exceed 4 × 103 based on the transmission calculation. Such an enhanced performance is driven by the resonant tunneling effect of the ON state, which significantly increases transmission across the FTJ when the ferroelectric polarization of HfO2 is pointing to the non-polar layer due to the aroused electron accumulation at the HfO2/MgS interface. Our results provide significant insight for the understanding and development of the FTJs based on the HfO2 ferroelectric/non-polar composite barrier. [ABSTRACT FROM AUTHOR]

Nitride perovskites ABN3 are an emerging and highly underexplored class of materials that are of interest due to their intriguing calculated ferroelectric, optoelectronic, and other functional properties. Incorporating novel A-site cations is one strategy to tune and expand such properties; for example, Gd3+ is compelling due to its large magnetic moment, potentially leading to multiferroic behavior. However, the theoretically predicted ground state of GdWN3 was a non-perovskite monoclinic structure. Here, we experimentally show that GdWN3−y crystallizes in a perovskite structure. High-throughput combinatorial sputtering with activated nitrogen is employed to synthesize thin films of Gd2−xWxN3−yOy with oxygen content y < 0.05. Ex situ annealing crystallizes a polycrystalline perovskite phase in a narrow composition window near x = 1. LeBail fits of synchrotron grazing incidence wide angle x-ray scattering data are consistent with a perovskite ground-state structure. Refined density functional theory calculations that included antiferromagnetic configurations confirm that the ground-state structure of GdWN3 is a distorted Pnma perovskite with antiferromagnetic ordering, in contrast to prior predictions. Initial property measurements find that GdWN3−y is paramagnetic down to T = 2 K with antiferromagnetic correlations and that the absorption onset depends on cation stoichiometry. This work provides an important path toward both the rapid expansion of the emerging family of nitride perovskites and understanding their potential multiferroic properties. [ABSTRACT FROM AUTHOR]

Designing highly efficient single-atom catalysts for converting nitrogen into ammonia under ambient temperature conditions holds significant importance. Current research predominantly focuses on electrocatalytic nitrogen fixation, but compared to that, photocatalytic nitrogen fixation requires only sunlight as an energy source, making it more environmentally friendly and cost-effective. Developing efficient nitrogen reduction reaction (NRR) photocatalysts presents a promising yet highly challenging task. Two-dimensional (2D) covalent organic frameworks (COFs) have garnered interest because of their elevated surface area and regular pore structure. This study employs density functional theory calculations to investigate the potential of NRR photocatalysts using the 2D COF TMT-TFPT-COF (TT-COF) supported with 18 different transition metal atoms (TM = Rh, Nb, Os, Mo, Ru, Pt, Ni, Co, V, Cu, Fe, Re, W, Cr, Ta, Mn, Pd, Ti). Through a four-step selection process, the most promising photocatalyst is identified. The results indicate that a single Re atom loaded onto TT-COF (Re@TT-COF) displays the optimal nitrogen fixation performance, demonstrating excellent catalytic activity and selectivity with a limiting potential of only −0.30 V. Furthermore, its good light absorption efficiency, suitable band edge position, and significant photo-generated electron potential enable spontaneous nitrogen fixation. Our study provides useful guidance for the rational design of COF-based NRR photocatalysts with high activity, stability, and selectivity. [ABSTRACT FROM AUTHOR]

Researchers are increasingly drawn to WSe2 due to its wide-ranging applications in electronic, optoelectronic, and catalytic materials. Like other transition metal dichalcogenides, it has different polymorphs, viz., 1T, 1T′, and 2H phases. A hexagonal close-packed layer-type structure of 2H-WSe2 is well studied and possesses a semiconducting behavior. However, the literature lacks a detailed study of crystallographic structure, facile synthesis, and different physical properties of 1T′-WSe2 (or 1T-phase). In this article, we synthesized a stable flower-like 1T′-WSe2 nanosheet in a facile solvothermal process. We also tried to explore the structural details using the Rietveld refinement of the powder x-ray diffraction data. The different Raman vibrational modes and phonon calculation based on the density functional theory (DFT) were performed to understand the stability of the 1T′-WSe2 phase. The flower-like 1T′-WSe2 nanosheet shows better catalytic activity for the hydrogen evolution reaction (HER) with an onset potential of −0.21 mV and overpotential 0.47 mV in comparison with the 2H-phase of WSe2 nanosheet. The DFT calculations also support the experimental data on the HER of 1T′-WSe2, establishing the suitability of the 1T′-phase for HER activity with the lowest value of the change in Gibbs free energy of hydrogen adsorption, Δ G H = 0.43 eV, for the monolayer. [ABSTRACT FROM AUTHOR]

Molecular conformation is an important characteristic feature of chemistry and physics, which exists in organic molecules. Based on the hydrogen bonding (HB) regulating conformations, we proposed a scheme to switch the stimulated Raman scattering peak from the symmetric vibration mode of −CαH2 (2878 cm−1) to that of −CβH2 (2937 cm−1) of n-propanol (NPA) aqueous solution with a volume fraction of 0.55. The dominant association structure can be converted from NPA–NPA to NPA–H2O by the HB network between H2O and NPA, and the HB structures were investigated through density functional theory calculations. The changes in intramolecular vibrational modes have effect on the relative abundances of NPA molecules by intermolecular HBs. This study can be extended to explore other organic molecular conformations in mixing solutions. [ABSTRACT FROM AUTHOR]

Kondo physics has long been interesting for studying correlated topology in isolation, as it occurs in heavy fermion compounds where myriad phenomena are well-separated in energy. We introduce magnetic topological Kondo semimetal phases of matter into the literature in this work to advance the understanding of correlated topological semimetal physics by studying a layered three-dimensional heterostructure in which two types of Kondo insulators are stacked alternatingly. In the heterostructures considered, one of these Kondo insulators is SmB6, a potential topological Kondo insulator, and the other one is an isostructural Kondo insulator AB6, where A is a rare-earth element, e.g., Eu, Yb, or Ce. We find that if the latter Kondo insulator orders ferromagnetically, the heterostructure generically becomes a magnetic Weyl Kondo semimetal, while antiferromagnetic order can yield a magnetic Dirac Kondo semimetal. We also confirm the realization of the magnetic Weyl (Dirac) Kondo semimetal phase in density functional theory calculations of the heterostructure of SmB6 and EuB6 (CeB6). Our results demonstrate that Kondo insulator heterostructures are a versatile platform for realizing correlated topological semimetal phases. [ABSTRACT FROM AUTHOR]

Magnetoelectric response in thin films is highly desirable for high-throughput and high-density microelectronic applications, like magnetic sensors. To sensitively detect the direction of magnetic field, the anisotropic magnetoelectric effect is required. Here, we artificially design an anisotropic magnetoelectric response in Sr2IrO4/SrTiO3 superlattices, where a strong (negligible) magnetoelectric response for magnetic fields along the z-direction (xy-plane) of Sr2IrO4/SrTiO3 interface was observed. A combination of perturbative calculations with numerical results and density functional theory calculations reveals that only the effective z-component Zeeman field within the Sr2IrO4 layers can change the electron occupation of the neighboring SrTiO3 layers, which is proportional to the polarization. Via controlling the periodicity of the superlattices, we can further control the anisotropy of magnetoelectric responses. This atomic-scale design of 3d/5d superlattices paves an alternative way toward controllable magnetoelectric effects with thin film integrations. [ABSTRACT FROM AUTHOR]

The temperature-dependent phonon thermal transport in CuInTe 2 is investigated by considering lattice thermal expansion, temperature-dependent anharmonicity, higher-order phonon–phonon interactions, and phonon renormalization with input from first-principles based density functional theory calculations. Incorporating these higher-order temperature-dependent effects reveals that the thermal conductivity varies with temperature as T − 1.59 consistent with experimental measurements ranging from T − 1.62 to T − 1.78 . Using the lowest-order theory or only temperature-dependent interatomic force constants or four-phonon scattering resulted in a wrong description of thermal transport physics. [ABSTRACT FROM AUTHOR]

The spin Hall effect (SHE) enables charge-to-spin conversion by electrical means and is promising for spintronic applications. Here, we report on the intrinsic spin Hall effect in the prototypical ferroelectric material HfO2 with charge doping using density functional theory calculations and theoretical analysis. We show that ferroelectric displacements are insensitive to charge doping and are sustained up to a large doping concentration of 0.4 electrons or holes per unit cell volume. In addition, the large spin Hall conductivity in the vicinity of the band edges is well preserved. Intriguingly, we demonstrate the giant spin Hall efficiency characterized by the sizable spin Hall angle of ∼ 0.1 in doped HfO2. These results add unexplored functionality to ferroelectric HfO2 and open opportunities for potential device applications. [ABSTRACT FROM AUTHOR]

Wide and ultrawide bandgap semiconductors, such as GaN, play a crucial role in high-power applications, yet their performance is often constrained by thermal management challenges. In this work, we introduce a high-quality interface between GaN and AlN, prepared through wafer-scale bonding and verified via high-resolution transmission electron microscopy and transport experiments. We experimentally measured the thermal boundary conductance of the GaN–AlN interface, achieving up to 320 MW/m2K at room temperature using an ultrafast optical technique and sensitivity examinations. Non-equilibrium atomistic Green's functions and density functional theory simulations were conducted to model the interface phonon modes and their contributions to thermal transport, demonstrating good agreement with the experimental results from 80 to 300 K. Additionally, we observed a size-dependent effect on the thermal boundary conductance related to the GaN film thickness from 180 to 450 nm, which we attributed to quasi-ballistic thermal transport through molecular dynamics simulations. Our study has demonstrated a scalable processing route for wafer-sized chip packaging and provides fundamental insights to mitigate near-junction thermal resistance. Further exploration of interface engineering could facilitate co-design strategies to advanced thermal management technologies. [ABSTRACT FROM AUTHOR]

The spin Hall effect (SHE) enables charge-to-spin conversion by electrical means and is promising for spintronic applications. Here, we report on the intrinsic spin Hall effect in the prototypical ferroelectric material HfO2 with charge doping using density functional theory calculations and theoretical analysis. We show that ferroelectric displacements are insensitive to charge doping and are sustained up to a large doping concentration of 0.4 electrons or holes per unit cell volume. In addition, the large spin Hall conductivity in the vicinity of the band edges is well preserved. Intriguingly, we demonstrate the giant spin Hall efficiency characterized by the sizable spin Hall angle of ∼ 0.1 in doped HfO2. These results add unexplored functionality to ferroelectric HfO2 and open opportunities for potential device applications. [ABSTRACT FROM AUTHOR]

When Pd nanoparticles dispersed on a glass substrate with nanometer order gaps are exposed to H2 gas, H atoms are adsorbed on the nanoparticle surface, and the electrical resistance between the nanoparticles increases because of the tunneling current suppression. In contrast, when Au nanoparticles are exposed to H2 gas, the resistance remains unchanged because H atoms are not adsorbed on the Au surface. Considering these behaviors, the change ratio of the electrical resistance is expected to be smaller when the surface of Pd nanoparticles is partially covered with Au. However, the experimental results show the opposite resistance change. Density functional theory simulation indicates that H atoms are adsorbed and absorbed on the pure Pd surface, but H atoms are adsorbed and tend to remain on the partially covered Pd surface. These results indicate that the decrease in the resistance due to the gap narrowing by hydrogen absorption occurs in Pd nanoparticles, but it does not occur in Au/Pd nanoparticles, resulting in a larger resistivity increase compared with the Pd nanoparticles. This result implies that in certain cases, the low reactivity of Au to H2 contributes to the enhancement of the electrical resistance response. [ABSTRACT FROM AUTHOR]

Polymetallic cationic spinel-type oxides are increasingly being used as catalysts for oxygen reduction/oxygen evolution reactions (ORR/OER). Here, we have modified the anti-spinel Co2MnO4 using a quenching strategy (CMO-Q) and demonstrated that the bidirectional migration of Co and Mn cations at the tetrahedral/octahedral positions is the essential reason for enhancing the ORR/OER performance. Electrochemical test results show that CMO-Q is better than Co2MnO4, OER initial potential decreased by 100 mV, and ORR current density increased from 4.2 to 7.3 mA cm−2 at 1600 rpm, with more stable CMO-Q-based zinc–air battery performance. Meanwhile, density functional theory calculations confirm that the primary factor contributing to the reduction of distance from the d-band center of Co and Mn to the Fermi level is the conductivity enhancement. This study offers insight into regulating the surface atomic migration and catalytic performance of spinel without compromising its stable structure. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) polymeric carbon nitride (PCN) materials have drawn broad attention as promising candidates for photocatalytic hydrogen evolution. However, it remains a significant challenge to simultaneously improve the visible light absorption, separation of photogenerated carriers, and activity. Herein, alkali metals doping PCN (e.g., C6N6 and C2N) are systematically investigated based on density functional theory. Different from the conventional notion of doping atoms as active sites, the actual active site is the intrinsic pyridine nitrogen surrounding the alkali metal. Compared to the change of Gibbs free energy value of −0.45 eV (−0.60 eV) for pristine C6N6 (C2N), Li or Cs doped PCN decreases to −0.03 eV (−0.10 eV) or 0.06 eV (−0.11 eV), respectively, benefitting from the adjustment of the 3p electronic state occupation for N atoms by charges transfer from alkali metal. Meanwhile, Li or Cs doping not only broadens the absorption of visible light by narrowing the band edge position but also promotes the separation of photogenerated electrons and holes by regulating their spatial separation, which is further confirmed by significant photocurrents for Li or Cs doped PCN based on nonequilibrium Green's function simulation. Our work could provide interesting insights into the mechanistic understanding and the highly efficient design of PCN materials in photocatalysis. [ABSTRACT FROM AUTHOR]

Molybdenene synthesized experimentally is the sole Dirac material with metallic properties so far [Sahu et al., Nat. Nanotechnol. 18, 1430 (2023)], exhibiting a wide array of unique and outstanding properties with potentially extensive applications. However, the free-standing molybdenene structure is not so stable, which highly limits its further exploitation. In this work, we employ density functional theory calculations and ab initio molecular dynamics simulations to investigate molybdenene monolayers functionalized with various elements (X = H, Li, Be, B, C, N, O, F, Na, Mg, Al, Si, P, S, Cl) at both basal surfaces, aiming at achieving the stable free-standing molybdenene derivatives. By evaluating the energetic, mechanical, dynamical, and thermodynamic properties, we confirm some stable monolayer structures of X-functionalized molybdenene (X = O, F, Al, Si, Cl), which are named as X-Molybdenene. Therefore, our findings stabilize the molybdenene via surface functionalization, which is crucial for future experimental validations and applications. [ABSTRACT FROM AUTHOR]

The recent discovery of ferroelectric properties in HfO2 has sparked significant interest in the fields of nonvolatile memory and neuromorphic computing. Yet, as device scaling approaches sub-nanometer dimensions, leakage currents present a formidable challenge. While tungsten (W) electrodes are favored over traditional TiN electrodes for their superior strain and interface engineering capabilities, they are significantly hampered by leakage issues. In this study, we elucidate a positive feedback mechanism attributable to W electrodes that exacerbates oxygen vacancy defects, as evidenced by density functional theory computations. Specifically, intrinsic oxygen vacancies facilitate the diffusion of W, which, in turn, lowers the formation energy of additional oxygen vacancies. This cascade effect introduces extra defect energy levels, thereby compromising the leakage characteristics of the device. We introduce a pre-annealing method to impede W diffusion, diminishing oxygen vacancy concentration by 5%. This reduction significantly curtails leakage currents by an order of magnitude. Our findings provide a foundational understanding for developing effective leakage suppression strategies in ferroelectric devices. [ABSTRACT FROM AUTHOR]

Laplace deep-level transient spectroscopy and photoluminescence have been used to demonstrate that the FeGa (0/−) acceptor level in dilute AlxGa1−xN (x ≤ 0.063) can be considered as a common reference level as expected for energy levels of transition metals in isovalent semiconductor compounds. Furthermore, the conduction and valence band offsets (ΔEC and ΔEV, respectively) in GaN/AlxGa1−xN heterojunctions, as a function of Al content for samples grown by the metalorganic vapor-phase epitaxy technique on native Ammono-GaN substrates, have been found. The band-offsets determined in this study are ΔEC = 1.17x eV and ΔEV = −0.95x eV over the range of x studied and are in good agreement with other experimental results reported for actual GaN/AlxGa1−xN heterojunctions as well as with the recent theoretical calculations based on hybrid density functional theory. Moreover, we confirmed that the band bowing effect related to compositional dependence in AlxGa1−xN is accommodated practically only in the conduction band as suggested by theoretical calculations. [ABSTRACT FROM AUTHOR]

High-entropy oxides (HEOs) with a multi-cation structure have attracted significant attention in the fields of electrochemistry owing to their high entropy stability and cocktail effect. However, there has been very limited research on the use of HEO in the field of sensing. In this work, we utilized FeCoNiCrMn high-entropy alloys as the precursor to synthesize (FeCoNiCrMn)3O4 HEO and investigated their crystal structure, microscopic morphology, elemental valence state information, and gas sensing performance. The sensor exhibited decent response to NO2 at room temperature (RT) without any modification or sensitization methods. To verify the gas sensing mechanism, we simulated the interaction between five metal elements in HEO and the NO2 molecules by density functional theory, which reveals a crucial synergistic effect from the multiple cations to enhance the adsorption and charge transfer of NO2 molecules. This work explores the application potential of (FeCoNiCrMn)3O4 in low-power gas sensors and enriches the material selection for RT sensors. [ABSTRACT FROM AUTHOR]

Dirac materials, due to their unique physical properties, hold vast prospects in both fundamental research and practical applications. Recently, the metallic Dirac material, molybdenene, has been synthesized. However, free-standing molybdenene is found to be dynamically unstable. We propose the use of F/Li to modify its structure and stabilize it. Based on density functional theory, density functional perturbation theory, and anisotropic Migdal–Eliashberg equations, we systematically investigate the electronic structures and superconducting properties of MoF and MoLi. The results indicate that both MoF and MoLi are intrinsic superconductors, with electron–phonon coupling constants of 0.49 and 0.74, respectively. Solving the superconducting gap equation yields a superconducting transition temperature of 7.5 K for MoLi. Further analysis suggests that the coupling between the out-of-plane component of Mo's d orbital electrons and the vibrations of Mo atoms contributes significantly to the electron–phonon coupling in MoLi. Our study lays the foundation for further applications of molybdenene. [ABSTRACT FROM AUTHOR]

Degradation and trap evolution in NiO/β-Ga2O3 heterojunction pn diodes under on-state electrical stress were investigated in this work using deep-level transient spectroscopy measurements and density functional theory (DFT) calculations. The decrease in turn-on voltage and forward current appears to correlate with an increase in the concentration of the compensating acceptor-like traps. From the energy level of EV + 1.3 eV, the corresponding acceptor-like traps can be attributed to the Ga vacancy complex with hydrogen (VGa-H). Interestingly, accompanied by the increase in VGa-H concentration, the self-trapped holes (STH) originally passivated by H may gradually recover. DFT calculations show a monotonous decrease in energy, suggesting the spontaneous diffusion of hydrogen from STH passivated sites to the adjacent VGa, which are generated under stress. This phenomenon leads to the recovery of STH and the generation of VGa-H. This investigation offers new insights into the degradation mechanisms of β-Ga2O3-based devices under electrical stress. [ABSTRACT FROM AUTHOR]

Multi-principal element alloys are a novel class of materials that are formed by combining multiple elements in high concentrations and show exceptional properties compared to conventional alloys. These alloys have high configurational entropy due to inherent atomic disorder. The Cauchy–Born rule is a popular homogenization method for linking atomistic to continuum length scales. In this Letter, we use ab initio density functional theory calculations to report that the Cauchy–Born rule, which holds in conventional alloys in the absence of defects, is not valid in multi-principal element alloys. The violation of the Cauchy–Born rule in these alloys is attributed to the presence of atomic disorder due to which the deformations are inhomogeneous. Our results also show the deviations in deformation are related to the magnitude of the stretch and shear by power laws. [ABSTRACT FROM AUTHOR]

X-ray absorption spectroscopy (XAS) is widely employed for structure characterization of graphitic carbon nitride (g-C3N4) and its composites. Nevertheless, even for pure g-C3N4, discrepancies in energy and profile exist across different experiments, which can be attributed to variations in structures arising from diverse synthesis conditions and calibration procedures. Here, we conducted a theoretical investigation on XAS of three representative g-C3N4 structures (planar, corrugated, and micro-corrugated) optimized with different strategies, to understand the structure–spectroscopy relation. Different methods were compared, including density functional theory (DFT) with the full core-hole (FCH) or equivalent core-hole (ECH) approximation as well as the time-dependent DFT (TDDFT). FCH was responsible for getting accurate absolute absorption energy; while ECH and TDDFT aided in interpreting the spectra, through ECH-state canonical molecular orbitals (ECH-CMOs) and natural transition orbitals (NTOs), respectively. With each method, the spectra at the three structures show evident differences, which can be correlated with different individual experiments or in between. Our calculations explained the structural reason behind the spectral discrepancies among different experiments. Moreover, profiles predicted by these methods also displayed consistency, so their differences can be used as a reliable indicator of their accuracy. Both ECH-CMOs and NTO particle orbitals led to similar graphics, validating their applicability in interpreting the transitions. This work provides a comprehensive analysis of the structure-XAS relation for g-C3N4, provides concrete explanations for the spectral differences reported in various experiments, and offers insight for future structure dynamical and transient x-ray spectral analyses. [ABSTRACT FROM AUTHOR]

Two-dimensional transition metal borocarbides with intrinsic magnetism have garnered significant research attention due to their potential applications in spintronics. Using density functional theory calculations, we designed a type of transition metal borocarbides with two distinct configurations, TMBC-Is and TMBC-IIs (TM = V–Co), and explored their electronic and magnetic properties. Our results demonstrate that all the studied systems exhibit both thermal and kinetic stability. Notably, four systems of MnBC-I/MnBC-II and FeBC-I/FeBC-II are robust ferromagnetic (FM) half metals (HMs) with Curie temperatures of 145, 180, 108, and 315 K. Expect FeBC-II monolayer, FM to antiferromagnetic transition occurs for three other FM HMs under 8%–10% compressive strains, while FM HM to FM semiconductor transition is found for MnBC-II monolayer under 8% tensile strain. These findings provide a promising way to design two-dimensional FM HMs, which hold potential applications in spintronics. [ABSTRACT FROM AUTHOR]

Many studies attribute the excellent properties of high-entropy alloys to the ordering-phenomena. It can be known from density functional theory that the macroscopic properties of the system can be described by the electron density. Electronegativity is related to electron density, and models describing ordering can be established based on electronegativity scales through machine learning. In this study, a large dataset was established and predicted the ordered state corresponding to the alloy composition. The accuracy of the model on the test set was 94%. Furthermore, this study used different methods to explain the machine learning model and learned more model information. [ABSTRACT FROM AUTHOR]

A topological phase transition in high-temperature superconductor FeTe1−xSex, occurring at a critical range of Se concentration x, underlies their intrinsic topological superconductivity and emergence of Majorana states within vortices. However, how Se concentration and distribution determine the electronic states, particularly the presence or absence of Majorana states, in FeTe1−xSex remains unclear. In this study, we combine density functional theory calculations with pz–dxz/yz-based analysis and Wannier-based Hamiltonian analysis to systematically explore the electronic structures of diverse FeTe1−xSex compositions. Our investigation reveals a nonlinear variation of the spin–orbit coupling (SOC) gap between pz and dxz/yz bands in response to the Se concentration x, with the maximum gap occurring at x = 0.5. The pz–pz and dx2−y2–pz interactions are found to be critical for pd band inversion. Furthermore, the distribution of Se significantly modulates the SOC gap, thereby influencing the emergence of Majorana states within local vortices. [ABSTRACT FROM AUTHOR]

Mechanoluminescent materials, which are capable of converting some ignored mechanical stimuli like friction, pressure, and distortion into useful photons, are gathering increasing attention nowadays, especially considering that a new round of energy crisis is sweeping across the globe. However, the wavelength of mechanoluminescence (ML) reported so far overlaps seriously with the solar spectrum, limiting the practical applications of mechanoluminescent materials to some extent. Here, we report the ultraviolet-C (UVC) ML from NaYF4:Pr3+ with the central wavelength at ∼250 nm, which is one of the shortest wavelengths for ML and is ascribed to the 1S0 → 3F4 transition of Pr3+. After being charged by x rays, NaYF4:Pr3+ is able to emit ML under the stimulation of external stress. The presence of UVC ML has been confirmed by both a spectrometer and a solar-blind camera. We confirm that the UVC ML belongs to the trap-controlled ML via thermoluminescence and related trap-filling-emptying measurements. With the aid of the density functional theory, we discuss the possible mechanism of the UVC ML from NaYF4:Pr3+. [ABSTRACT FROM AUTHOR]

Mechanoluminescent materials, which are capable of converting some ignored mechanical stimuli like friction, pressure, and distortion into useful photons, are gathering increasing attention nowadays, especially considering that a new round of energy crisis is sweeping across the globe. However, the wavelength of mechanoluminescence (ML) reported so far overlaps seriously with the solar spectrum, limiting the practical applications of mechanoluminescent materials to some extent. Here, we report the ultraviolet-C (UVC) ML from NaYF4:Pr3+ with the central wavelength at ∼250 nm, which is one of the shortest wavelengths for ML and is ascribed to the 1S0 → 3F4 transition of Pr3+. After being charged by x rays, NaYF4:Pr3+ is able to emit ML under the stimulation of external stress. The presence of UVC ML has been confirmed by both a spectrometer and a solar-blind camera. We confirm that the UVC ML belongs to the trap-controlled ML via thermoluminescence and related trap-filling-emptying measurements. With the aid of the density functional theory, we discuss the possible mechanism of the UVC ML from NaYF4:Pr3+. [ABSTRACT FROM AUTHOR]

The electronic and transport properties of aluminum-graphene composite materials were investigated using the ab initio plane wave density functional theory. The interfacial structure is reported for several configurations. In some cases, the face-centered aluminum (111) surface relaxes in a nearly ideal registry with graphene, resulting in a remarkably continuous interface structure. The Kubo–Greenwood formula and space-projected conductivity were employed to study electronic conduction in aluminum single- and double-layer graphene-aluminum composite models. The electronic density of states at the Fermi level is enhanced by the graphene for certain aluminum–graphene interfaces, thus improving electronic conductivity. In double-layer graphene composites, conductivity varies non-monotonically with temperature, showing an increase between 300 and 400 K at short aluminum-graphene distances, unlike the consistent decrease in single-layer composites. [ABSTRACT FROM AUTHOR]

The development of highly efficient near infrared (NIR) luminescence materials is crucial for advancing the next generation compact light sources. However, the realization of target material with emission in the NIR-II spectral region (1000–1700 nm) remains a major challenge. Herein, a NIR-II emission phosphor Ba3BPO7:Mn5+ peaking at 1176 nm with a full width of half maximum of 22 nm is demonstrated via a selective site occupancy engineering strategy. Upon 660 nm red-light excitation, high internal quantum efficiency of 50.6% and external quantum efficiency of 30.5% are obtained in this phosphor. Density functional theory calculations and structural analyses provide an understanding of stabilizing pentavalent manganese in Ba3BPO7:Mn5+. The highly efficient NIR-II emission is mainly ascribed to the relatively high distorted tetrahedral crystal field environment of Mn5+ in this system and the stable valence state. Combining this phosphor with 660 nm red-light chip, we fabricate a light emitting diode with NIR-II output power of 19.2 mW@300 mA, which shows promising applications in anti-counterfeiting, special information identification, etc. This work provides some important insights into the design of highly efficient Mn5+ based NIR-II emission and the emerging applications. [ABSTRACT FROM AUTHOR]

The development of highly efficient near infrared (NIR) luminescence materials is crucial for advancing the next generation compact light sources. However, the realization of target material with emission in the NIR-II spectral region (1000–1700 nm) remains a major challenge. Herein, a NIR-II emission phosphor Ba3BPO7:Mn5+ peaking at 1176 nm with a full width of half maximum of 22 nm is demonstrated via a selective site occupancy engineering strategy. Upon 660 nm red-light excitation, high internal quantum efficiency of 50.6% and external quantum efficiency of 30.5% are obtained in this phosphor. Density functional theory calculations and structural analyses provide an understanding of stabilizing pentavalent manganese in Ba3BPO7:Mn5+. The highly efficient NIR-II emission is mainly ascribed to the relatively high distorted tetrahedral crystal field environment of Mn5+ in this system and the stable valence state. Combining this phosphor with 660 nm red-light chip, we fabricate a light emitting diode with NIR-II output power of 19.2 mW@300 mA, which shows promising applications in anti-counterfeiting, special information identification, etc. This work provides some important insights into the design of highly efficient Mn5+ based NIR-II emission and the emerging applications. [ABSTRACT FROM AUTHOR]

Ternary two-dimensional (2D) monoclinic Nb2SiTe4 has garnered significant attention for its potential applications in anisotropic photoelectronics. Yet, its intrinsic indirect bandgap nature and low hole mobility, attributed to the short Nb–Nb dimer configurations, hinder the efficient photogenerated carrier separation and transport. In this Letter, using density functional theory calculations, we demonstrate the interlayer intercalation of Si results in the formation of a metastable orthorhombic Nb2SiTe4 structure devoid of detrimental short Nb–Nb dimers. Notably, this Si intercalation leads to a remarkable reduction of hole effective masses of orthorhombic Nb2SiX4 (X = S, Se, and Te), a crucial factor for achieving high carrier mobility. Taking the orthorhombic Nb2SiTe4 monolayer as an example, the calculated hole mobility (>100 cm2 V−1 s−1) is comparable in magnitude to the respectable hole mobility observed in multiple layers of the monoclinic Nb2SiTe4. To simultaneously enhance electron and hole mobility, we establish a van der Waals junction between the monoclinic and orthorhombic Nb2SiTe4 structures, achieving high and comparable carrier mobilities. The Nb2SiTe4 junction exhibits a nearly direct bandgap of 0.35 eV, rendering it suitable for infrared light harvesting. Furthermore, carriers within the Nb2SiTe4 junction become spatially separated across different layers, resulting in an intrinsic built-in electric field, which is superior for efficient photo-generated charge separation and decreases the potential nonradiative carrier recombination. Our findings highlight the impact of cation coordination engineering on the electronic and optical properties of 2D Nb2SiTe4 and provide a feasible solution to achieve better carrier transport in low-dimensional photovoltaic functionalities. [ABSTRACT FROM AUTHOR]

The integration of two-dimensional heterostructure materials remains a fundamental way for the manipulation of spintronics in practical applications. Here, we predicted the transform of stripy antiferromagnetic (AFM) CoI2 and MnBr2 monolayers to interlayer AFM CoI2/MnBr2 heterostructure with intralayer ferromagnetic orders by using density functional theory. Interestingly, the CoI2/MnBr2 heterostructure exhibits a typical bipolar magnetic semiconducting state with type-I band alignments. Moreover, the half-metal/semiconductor transition and spin-up/spin-down polarization switching in CoI2/MnBr2 heterostructure can be effectively triggered by electron/hole doping. Our study provides the potential of AFM spintronics for information storage and processing. [ABSTRACT FROM AUTHOR]

Charge hopping transport is typically modeled by Marcus theory with the coupling strengths and activation energies extracted from the constrained density functional theory. However, such a method may not be a practical route for amorphous materials due to the tremendous amount of hopping paths, therefore computationally unreachable. This work presents a general approach combining the a b initio method and model Hamiltonian, yielding similar results to constrained density functional theory. Such an approach is computationally efficient, allowing us to consider all 23 220 hopping paths between oxygen vacancies in our demonstrated amorphous hafnium dioxide model containing 324 atoms. Based on these hopping rates, charge mobility in amorphous hafnium dioxide is investigated as a function of oxygen vacancies concentration. It is found that a minimum oxygen vacancies concentration of 0.7 × 10 21 cm−3 is required to enable the connectivity of the charge hopping network. [ABSTRACT FROM AUTHOR]

A critical stage in developing high-density memristors is addressing the sneak current within the crossbar architecture. One of the effective strategies to endow the memristive cell with the ability to prevent sneak currents when it is in a low resistance state is to give it an inherent diode, known as a self-rectifying memristive cell. This study demonstrates the Schottky diode inside the MAPbI3-based memristive cell, a consequence of its interaction with the tungsten (W) electrode. The performance of memory devices is reliable with low-voltage operation, a resistance window having over ten of magnitude, and the retention time remains over 104 s. Prominently, the self-rectifying behavior is sustainable over 150 cycles and exhibits a rectification ratio of approximately 102 times. Density functional theory calculation reveals the presence of unoccupied gap states on an interfaced MAPbI3 surface, serving as electron trapping states during the charge transport across the W/MAPbI3 Schottky interface. Consequently, the conduction mechanism is primarily governed by an interfacial-controlled model, notably Schottky emission. This improvement promises to eliminate sneak currents in future crossbar array fabrication. [ABSTRACT FROM AUTHOR]

Bi2S3 has attracted significant interest due to its unique optical, electrical, and photosensitive properties. The utilization of pressure has been substantiated as a proficient technique in modulating the optoelectronic characteristics of functional materials and has garnered increasing attention. In this work, the photoresponse of Bi2S3 upon compression was systematically investigated in combination with in situ photocurrent measurements, Raman spectroscopy, absorption spectroscopy, and density functional theory calculations. Under pressure, Bi2S3 exhibits two distinct photoresponses. Bi2S3 exhibits an obvious positive photoresponse in the pressure range from 0.5 to 9.7 GPa. The photocurrent shows a rapid increase with increasing pressure and reaches the maximum value at 4.0 GPa, which is 5.6 times of the initial value. Interestingly, above 30.3 GPa, Bi2S3 shows a negative photocurrent response, which can be attributed to the photothermal effect caused by pressure-induced metallization phase transition. Our findings provide insight into the modulation of the optoelectronic properties of Bi2S3 and offer more possibilities in the further optimizing design optoelectronic devices based on Bi2S3. [ABSTRACT FROM AUTHOR]

Bi2S3 has attracted significant interest due to its unique optical, electrical, and photosensitive properties. The utilization of pressure has been substantiated as a proficient technique in modulating the optoelectronic characteristics of functional materials and has garnered increasing attention. In this work, the photoresponse of Bi2S3 upon compression was systematically investigated in combination with in situ photocurrent measurements, Raman spectroscopy, absorption spectroscopy, and density functional theory calculations. Under pressure, Bi2S3 exhibits two distinct photoresponses. Bi2S3 exhibits an obvious positive photoresponse in the pressure range from 0.5 to 9.7 GPa. The photocurrent shows a rapid increase with increasing pressure and reaches the maximum value at 4.0 GPa, which is 5.6 times of the initial value. Interestingly, above 30.3 GPa, Bi2S3 shows a negative photocurrent response, which can be attributed to the photothermal effect caused by pressure-induced metallization phase transition. Our findings provide insight into the modulation of the optoelectronic properties of Bi2S3 and offer more possibilities in the further optimizing design optoelectronic devices based on Bi2S3. [ABSTRACT FROM AUTHOR]

The anisotropic permittivity parameters of monoclinic single crystal lutetium oxyorthosilicate, Lu2SiO5 (LSO), have been determined in the terahertz spectral range. Using terahertz generalized spectroscopic ellipsometry (THz-GSE), we obtained the THz permittivities along the a, b, and c ⋆ crystal directions, which correspond to the ε a , ε b , and ε c ⋆ on-diagonal tensor elements. The associated off diagonal tensor element ε a c ⋆ was also determined experimentally, which is required to describe LSO's optical response in the monoclinic a–c crystallographic plane. From the four tensor elements obtained in the model fit, we calculate the direction of the principal dielectric axes in the a–c plane. We find good agreement when comparing THz-GSE permittivities to the static permittivity tensors from previous infrared and density functional theory studies. [ABSTRACT FROM AUTHOR]

Developing methods to understand and control defect formation in nanomaterials offers a promising route for materials discovery. Monolayer MX2 phases represent a particularly compelling case for defect engineering of nanomaterials due to the large variability in their physical properties as different defects are introduced into their structure. However, effective identification and quantification of defects remain a challenge even as high-throughput scanning transmission electron microscopy methods improve. This study highlights the benefits of employing first principles calculations to produce digital twins for training deep learning segmentation models for defect identification in monolayer MX2 phases. Around 600 defect structures were obtained using density functional theory calculations, with each monolayer MX2 structure being subjected to multislice simulations for the purpose of generating the digital twins. Several deep learning segmentation architectures were trained on this dataset, and their performances evaluated under a variety of conditions such as recognizing defects in the presence of unidentified impurities, beam damage, grain boundaries, and with reduced image quality from low electron doses. This digital twin approach allows benchmarking different deep learning architectures on a theory dataset, which enables the study of defect classification under a broad array of finely controlled conditions. It thus opens the door to resolving the underpinning physical reasons for model shortcomings and potentially chart paths forward for automated discovery of materials defect phases in experiments. [ABSTRACT FROM AUTHOR]

Interface coupling is considered as an effective approach to manipulate the physical properties of heterostructures. Here, we fabricated the heterostructure composed of two-dimensional (2D) ferromagnetic Fe3GeTe2 (FGT) and VI3. The experimental findings demonstrated that VI3 plays a pivotal role in modulating the spin texture of FGT through close-range coupling, leading to a substantial increment in the coercive field (HC) of FGT by ∼150%. To rational our findings, density functional theory calculations were employed to investigate the underlying mechanism. We propose that the spin pining effect at the interface contributes significantly to the observed enhancement of magnetic anisotropy. This research expands our understanding of interface effects and offers a promising method for the magnetism manipulation in 2D ferromagnetic systems. [ABSTRACT FROM AUTHOR]

Regulating the interlayer transfer of excited charges is challenging but crucial for high-efficiency photoelectric conversion devices based on semiconductor heterojunction. In this work, the interlayer transfer and recombination of excited charges are investigated for the heterobilayers based on monolayer MoSSe and WS2 by combining density functional theory calculation with nonadiabatic molecular dynamics simulation. Our results reveal that the heterobilayers possess type-II band alignments and the interface engineering from S–Se to S–S stacking configuration reverses the spatial distribution of valence and conduction bands from MoSSe and WS2 to WS2 and MoSSe layers, respectively, which produces interlayer transfer of excited charges in opposite direction. The interface engineering also causes the delocalization of out-of-plane phonon states from the WS2 layer to both WS2 and MoSSe layers. This delocalized character in S–S configuration facilitates the simultaneous coupling of out-of-plane phonon states with the localized donor and acceptor electronic states, accelerates the motion of interface atoms, and reduces the band energy differences, which synergistically promote interlayer transfer of excited charges. As a result, the interlayer transfer of excited charges in S–S configuration is faster than that in S–Se configuration. Our investigation demonstrates that delocalizing phonon states through interface engineering can regulate electron–phonon coupling and interlayer transfer of excited charges. [ABSTRACT FROM AUTHOR]

The ultrawide bandgap semiconducting property of materials is key to the development of advanced optoelectronic nanodevices with potential applications in flexible and transparent electronics and high-power radio frequency electronics. Here, a series of nonmagnetic porous XO (X = Be, Mg, Zn, and Cd) biphenylene- and graphenylene-type structures are predicted using the first-principles calculations based on the density functional theory (DFT). DFT results proved that XO monolayers exhibit excellent energetic, mechanical, dynamic, and thermal stabilities. The Heyd–Scuseria–Ernzerhof calculations show that the XO-biphenylene and graphenylene structures exhibit narrow, wide, ultra-wide, and insulating semiconducting electronic properties. We then investigated the bandgaps dependent on the thickness of the XO layer and found that the bandgaps decrease uniformly as the number of XO-biphenylene and -graphenylene layers increases. These remarkable electronic properties of XO structures expand the potential of porous oxide materials for the development of practical optoelectronic and thermoelectric nanodevices. [ABSTRACT FROM AUTHOR]

The all-inorganic perovskite CsPbCl3 has attracted significant attention for its excellent carrier mobility and high optical absorption coefficient, demonstrating great potential for use as a high-performance photodetector. However, the severe toxicity of lead and its narrow-band response in the UV region pose a huge challenge to the application of the perovskite. In this study, we reduce the toxicity of CsPbCl3 by substituting Mn atoms for Pb atoms and introduce a wide-bandgap semiconductor p-GaN to improve the photoresponse of CsPbCl3 in the UV region. Mn-doped CsPbCl3/GaN heterojunction is prepared by transferring the synthesized Mn-doped CsPbCl3 precursor solution onto p-GaN substrates via the spin-coating method. The morphology and optical properties of the heterojunction are characterized in various ways, and the current–voltage characteristics and optical response properties of the Mn-doped CsPbCl3/GaN heterojunction photodetector are also measured. The rectification behavior and UV–visible dual-band response of the heterojunction are demonstrated, with the response in the UV region extending to 320 nm. Furthermore, the calculations, which are based on density functional theory, confirm that the optical absorption of the Mn-doped CsPbCl3/GaN heterojunction is significantly enhanced compared with that of the isolated material. Meanwhile, a type-II energy band arrangement is found at the heterojunction interface. The results of this study suggest that Mn-doped CsPbCl3/GaN heterojunctions are potential candidates for use as UV–visible dual-band photodetectors. [ABSTRACT FROM AUTHOR]

The symmetric and anti-symmetric stretching vibrations of C–H extensively exist in organic molecules, which constantly arise together in Raman spectroscopy. In this study, a method was presented to switch stimulated Raman scattering peak from symmetric vibrations (2870 cm−1) to anti-symmetric vibrations (2924 cm−1) of –CH2 by regulating the hydrogen bonding (HB) associated through intermolecular and intramolecular in diethylene glycol (DEG) molecules. Such dominant association structure can be converted from DEG-DEG to DEG-H2O in the aqueous DEG solutions. The interaction between H2O and DEG was investigated through the density functional theory calculation. The changes in intermolecular HB have effects on the intramolecular vibrational modes by the intermolecular forces and symmetry of the DEG molecule. This study has exciting potential prospect and can be extended to other mixing solutions. [ABSTRACT FROM AUTHOR]

As the demand for high-capacity battery materials continues to grow, the exploration of the interaction mechanisms between Li/Na/K atoms and electrode materials has gained tremendous attention. In this study, we introduce a descriptor (ɛɑ) aimed at efficiently identifying high-performance electrode materials, specifically from two-dimensional transition metal chalcogenides and C and N compounds (MXenes). Our density functional theory calculations disclose a robust linear relationship between this descriptor and the adsorption energy (Ead), represented as Ead = ɛɑ + b. The fitting parameters, ɛɑ and b, are individually linked to the inherent properties of the substrate and adsorbate. Explicitly, the descriptor ɛɑ represents the capacity of the electrode material to accommodate an extra electron, while the intercept b is determined by the ionization energy (EIP) of alkali atoms and the coupling energy (Ecp) between the cation to the negatively charged substrate. This finding serves as a practical guide for designing high-capacity battery materials and paves the way for future advancements in this field. [ABSTRACT FROM AUTHOR]

Ga2O3 is an ultrawide-bandgap semiconductor with a variety of crystal configurations, which has the potential for a variety of applications, especially in power electronics and ultraviolet optoelectronics. However, there has been no single interatomic potential reported for Ga2O3 polymorphs in terms of molecular dynamics prediction of thermal conductivity. Here, one interatomic potential has been developed based on neural networks, which has the clear advantages of consuming less computational power than density functional theory and has high accuracy in predicting the thermal conductivity of the three polymorphs of Ga2O3. Using the neuroevolution potential, the thermal conductivity values at 300 K have been predicted. Hence, the κ[average-α] was 67.2% that of β-Ga2O3, and the κ[average-ε] was only 26.4% that of β-Ga2O3. The possible reasons for the discrepancies in thermal conductivity values in various crystal types and orientations have been explored. As a result, it could be shown that the contribution of low-frequency phonons to thermal conductivity was very significant in Ga2O3, and a unit cell with low symmetry and high atomic number would negatively impact the thermal conductivity of the material. In this work, a scheme has been proposed for accurately predicting the thermal conductivity of Ga2O3 and a relatively accurate value of the thermal conductivity of ε-Ga2O3 has been achieved, which could also provide an atomic-scale perspective for the insight into the thermal conductivity differences among α, β, and ε-Ga2O3. [ABSTRACT FROM AUTHOR]

Ga2O3 is an ultrawide-bandgap semiconductor with a variety of crystal configurations, which has the potential for a variety of applications, especially in power electronics and ultraviolet optoelectronics. However, there has been no single interatomic potential reported for Ga2O3 polymorphs in terms of molecular dynamics prediction of thermal conductivity. Here, one interatomic potential has been developed based on neural networks, which has the clear advantages of consuming less computational power than density functional theory and has high accuracy in predicting the thermal conductivity of the three polymorphs of Ga2O3. Using the neuroevolution potential, the thermal conductivity values at 300 K have been predicted. Hence, the κ[average-α] was 67.2% that of β-Ga2O3, and the κ[average-ε] was only 26.4% that of β-Ga2O3. The possible reasons for the discrepancies in thermal conductivity values in various crystal types and orientations have been explored. As a result, it could be shown that the contribution of low-frequency phonons to thermal conductivity was very significant in Ga2O3, and a unit cell with low symmetry and high atomic number would negatively impact the thermal conductivity of the material. In this work, a scheme has been proposed for accurately predicting the thermal conductivity of Ga2O3 and a relatively accurate value of the thermal conductivity of ε-Ga2O3 has been achieved, which could also provide an atomic-scale perspective for the insight into the thermal conductivity differences among α, β, and ε-Ga2O3. [ABSTRACT FROM AUTHOR]

A vanadium diselenide (VSe2) monolayer is a two-dimensional (2D) magnetic material that exhibits ferromagnetic ordering at room temperature and exceptional metal-ion storage capacity, making it useful in spintronics and energy storage applications. However, a robust correlation between the magnetic and electrochemical properties of VSe2 remains to be established. In this study, first-principles density functional theory calculations were performed to investigate the effect of increasing Li-ion concentrations on the magnetic properties, particularly the magnetic ground state of the VSe2 monolayer. The results indicate that, as the concentration of Li ions on the surface of VSe2 monolayer increases, magnetic phase transitions occur, leading to a shift from the intrinsic ferromagnetic (FM) state to antiferromagnetic (AFM) and non-magnetic ground states. Analyses of the diffusion properties of ferromagnetic and antiferromagnetic VSe2 monolayers revealed a considerable (∼71%) increase in the Li-ion diffusion energy barrier for the AFM state compared to the FM state. This implies that FM-VSe2 facilitates relatively faster diffusion of Li ions than AFM-VSe2. Therefore, the Li-ion concentration-induced phase change in the VSe2 monolayer leads to variable adsorption and diffusion characteristics, which will have significant implications for its use in Li-ion battery anodes. [ABSTRACT FROM AUTHOR]

The design of polarization-sensitive, stable self-powered, and broadband photoresponse optoelectronic devices remains a big challenge. Here, the influence of vacancy defects on the electronic structure properties of CsCu2I3 has been studied by density functional theory, which reveals the feasibility of their application in the field of optoelectronic devices, and then, their photogalvanic effects have been investigated based on quantum transport simulations. The results show that the pristine CsCu2I3 and I-vacancy devices indeed generate robust photocurrents under irradiation with linearly polarized light at the near ultraviolet to the visible wavelength without bias, demonstrating the self-powered and broadband response of the devices. The extinction ratios of the pristine CsCu2I3 and I-vacancy devices were 9.84 and 33.02 at zero bias, respectively. In addition, the I-vacancy device exhibits an ultra-high extinction ratio of up to 69.7 at 0.2 V. These results demonstrate potential applications of CsCu2I3-based devices in high performance, low power, and polarization detection. [ABSTRACT FROM AUTHOR]