Deposition Route Research Articles

Low-loading and ultrasmall Ir nanoparticles coupled with Ni/nitrogen-doped carbon nanofibers with Pt-like hydrogen evolution performance in both acidic and alkaline media

The construction of highly active and durable electrocatalysts for hydrogen production from water electrolysis in a wide pH range is crucial for the sustainable development of clean energy. In this work, low-loading and ultrasmall Ir nanoparticles decorated on the surface of Ni/nitrogen-doped carbon nanofibers (NCNFs) are rationally constructed through a simple chemical reduction deposition route. Benefiting from the rich electrochemical active sites and excellent electrical conductivity, the obtained Ni-NCNFs-Ir catalyst exhibits superior hydrogen evolution reaction (HER) activities in both acidic and alkaline solutions. Specifically, the optimized 0.1Ni-NCNFs-5Ir catalyst with Ir content of 6.0 wt% exhibits remarkable low overpotentials of 22 and 25 mV at 10 mA cm−2 in 0.5 M H2SO4 and 1 M KOH, respectively, which are better than many other reported Ir- or Ni-based electrocatalysts. In addition, the prepared 0.1Ni-NCNFs-5Ir catalyst shows favorable durability. Our theoretical results reveal that the relevant C- and Ir-sites jointly contribute to the high HER catalytic property of the Ni-NCNFs-Ir system, and two complicated electron transfer processes (Ni → C → N and Ir → C → N) are beneficial to promote the electrocatalytic performance. This work provides a meaningful strategy to develop high-efficiency HER electrocatalysts in a wide pH range.

Improving the composition and multifunctional properties of amorphous boron nitride films prepared by post-annealing assisted femtosecond pulsed laser deposition method

Amorphous boron nitride (aBN) materials have similar density to crystalline phases and retain many unique electronic properties, valuable chemical inertness and high thermal stability characteristics. However, the current research on aBN materials has mainly focused on the synthesis and electrical properties of ultrathin aBN films. In this study, we developed a post-annealing assisted femtosecond laser deposition route towards stoichiometric, continuous, and multifunctional aBN films with thickness values of ∼1 μm. A series of boron nitride films were deposited on silicon wafers using a 1030 nm, 300 fs laser with a pulse energy of ∼1 mJ and a high repetition rate of 2 kHz to ablate a hexagonal boron nitride target. The deposited films were then annealed at 900 °C in a nitrogen atmosphere. The structures and chemical compositions of these obtained films were analysed by X-ray diffraction and X-ray photoelectron spectroscopy. Fourier transform infrared and nano-scratch tests were performed to measure the infrared optical and frictional properties of the adhered films. An infrared thermal imager was used to investigate the heat-dissipation performance of these films. The results indicate the components of the aBN film are further purified, the number of large heterogeneous particles is effectively reduced, and the surface becomes smooth after post-annealing treatment. This improvement promotes the transfer of heat flux and increases the transmittance in the mid-infrared light band. The significant effect mechanisms of the post-annealing treatment on the enhancement of the composition and multifunctional properties of aBN films prepared by the femtosecond pulsed laser were provided. The uniform coverage of the aBN films on the substrates, as well as the mid-infrared optical transparency and the protective performance are highly valuable and practical for infrared window protection applications.

Vacuum-Deposited Wide-Bandgap Perovskite for All-Perovskite Tandem Solar Cells.

All-perovskite tandem solar cells beckon as lower cost alternatives to conventional single-junction cells. Solution processing has enabled rapid optimization of perovskite solar technologies, but new deposition routes will enable modularity and scalability, facilitating technology adoption. Here, we utilize 4-source vacuum deposition to deposit FA0.7Cs0.3Pb(IxBr1-x)3 perovskite, where the bandgap is changed through fine control over the halide content. We show how using MeO-2PACz as a hole-transporting material and passivating the perovskite with ethylenediammonium diiodide reduces nonradiative losses, resulting in efficiencies of 17.8% in solar cells based on vacuum-deposited perovskites with a bandgap of 1.76 eV. By similarly passivating a narrow-bandgap FA0.75Cs0.25Pb0.5Sn0.5I3 perovskite and combining it with a subcell of evaporated FA0.7Cs0.3Pb(I0.64Br0.36)3, we report a 2-terminal all-perovskite tandem solar cell with champion open circuit voltage and efficiency of 2.06 V and 24.1%, respectively. This dry deposition method enables high reproducibility, opening avenues for modular, scalable multijunction devices even in complex architectures.

Wafer-Scale High-Detectivity Near-Infrared PbS Detectors Fabricated from Vapor Phase Deposition

The commercialization of uncooled lead-salt photoconductive (PbX PC) detectors has been restricted by the low-yield of standard chemical bath deposition (CBD) manufacturing technology. As an iterative solution, herein, a novel vapor phase deposition (VPD) route is demonstrated by fabricating the 3 in. wafer-scale uniform PbS sensitized films with high detectivity. The morphological evolution suggests that the self-assembled rod-like microstructure, which is dominated by the I2/PbS flux ratio in the VPD process, is the key to triggering the near-infrared (NIR, 1–3 μm) response of the PbS-sensitized films. The maximum peak detectivity of VPD-PbS NIR detector of 1.9 × 1011 cm Hz1/2 W–1 is achieved after optimizing the sensitization-condition dependence of PbS detector’s performance. The high performance of wafer-scale VPD-PbS PC detectors, which attains the same performance as standard CBD-PbS detectors, manifests that the VPD technology opens up a new avenue to the industrialization of uncooled lead-salt PC detectors.

Unusual Micro Carbon Rods Formed from PET Plastic via Pyrolysis and Annealing in CO2/He Co-Gas

This study investigates the transformation of activated carbon (AC) powder, derived from polyethylene terephthalate (PET) through pyrolysis, into a specific type of short cylindrical carbon. This carbon-to-carbon (C-C) transformation was completed by annealing the AC powder in a co-gas atmosphere of He and CO2. This produces low-porous, amorphous, and micro carbon rods (MCR) in micron size. It is suggested that a so-far unknown growth mechanism originates from the oxidation role of CO2, initiating the curving of polycyclic aromatic hydrocarbons (PAHs) sheets. This annealing step was followed by layer-by-layer sheet stacking steps to render the thick rods. This thickness is also created by the simultaneous occurrence of rare carbon nanotubes, supposedly formed initially from curling a small sheet of PAH surrounding carbon nanoparticles to create a tube template for subsequent cylindrical growth. This is the first example of CNT growth through C-C transformation rather than the other vapor deposition routes. As the main product, MCR is amorphous and fairly porous, with an average aspect ratio greater than 10, which possesses potential applications as a mechanical reinforcing or energy-attenuation filler for different composites.

Highly Conductive Tungsten-Doped Tin(IV) Oxide Transparent Electrodes Delivered by Lattice-Strain Control

Alternatives to tin-doped indium oxide transparent electrodes are needed to meet the growing demand for modern electronic devices. Here, we present a chemical vapor deposition route to tungsten-doped SnO2 thin films with resistivities as low as 5.9 × 10–4 Ω cm and electron mobilities as high as 30 cm2 V–1 s–1. Le Bail fitting of the XRD data showed that the substitutional dopant, tungsten(V) causes minimal distortion to the SnO2 unit cell due to its radius closely matching that of tin(IV). Furthermore, crystallographic preferential orientation in the [200] direction that is thought to facilitate a high mobility was also seen. X-ray photoelectron spectroscopy analysis suggests that W is present in the +5 state, as opposed to +6, therefore minimizing ionized impurity scattering, hence also helping achieve the observed high electron mobilities. The tungsten-doped films had optical band gaps of 3.7 eV, thus enabling transparency to visible light.

Enhanced optoelectronic and supercapacitive performance of electrodeposited Mn3O4 thin film prepared from two-electrode: An effect of Zn-ion incorporation

Here in, we report electrodeposited Mn3O4 thin film doped with various level of Zn dopant (0≤x≤5.0,%), on a layer of indium tin oxide (ITO) on glass substrate. The deposition route involves the use of two-electrode electrochemical cell system comprising graphite and the substrate as counter and working electrodes, respectively. Some surface properties such as those of morphological, crystal structure, optical, electrical and electrochemical were studied to evaluate the films’ potentials in energy conversion and storage devices. Microstructural studies revealed the films grew with isotropic morphology of good tetragonal shaped crystal structure with even distribution and possessing required surface area on the substrate surfaces. Raman prominent peak at 659 cm −1 wave number indicates a typical A1g Raman vibrating mode of Mn2+ in a Mn3O4 spinel structure. The crystallite size and microstrain values were found varying from 38 to 43 nm and 5.6 × 10−3 to 3.2 × 10−3, with respect to increase in dopant content, respectively. Energy band gap and Urbach energy were varied from 3.28 to 2.68 eV and 1.59 to 2.17 eV with increasing level of dopant content, accordingly. Electrochemical charge storage area capacitance (12.62 to 21.35 mF cm −2)/capacity (5.1 to 8.1μAh cm −2) and rate capability of Mn3O4 electrode were found to improve with Zn dopant. The work therefore discusses the tailoring of band absorption and supercapacitive characteristic of electrodeposited Mn3O4 thin film with Zn-doping for enhanced energy application.

Influence of ultrafast microwave deposition on morphology and growth mechanism of WO3 nanosheet photoanode for efficient bacterial inactivation and decomposition of organic pollutants

We report the ultrafast synthesis of WO3 nanosheet array photoanode on fluorine-doped tin oxide-coated glass without a seed layer by microwave-assisted deposition route. The ultrafast microwave-assisted synthesis at various microwave deposition cycles resulted in tailored WO3 morphologies with a monoclinic structure. The photoanode growth mechanism and effect of morphology tuning on the photoelectrochemical activities of WO3 photoanodes were studied in detail. Under one sun irradiation, the microwave-assisted WO3 photoanode prepared at four cycles (WO3-4 MW) exhibited a photocurrent density of 1.1 mA/cm2 at 1.0 V versus Ag/AgCl, whereas the WO3 photoanode prepared at two cycles (WO3-2 MW) achieved 0.68 mA/cm2. Further, hydrogen treatment of optimum WO3-4 MW photoanodes at 300 °C, 20 min and exhibited a high photoelectrochemical (PEC) degradation efficiency of Orange II dye (∼99 %/180 min) and BPA (98.5 % in 30 min). Additionally, ∼97 % E. Coli bacterial PEC inactivation was achieved within 120 min over H2-WO3-4 MW under one sun illumination irradiation. Also, plausible charge recombination/separation processes in microwave-assisted WO3/FTO and H2-WO3-4 MW photoanodes were also reported.

Low-Temperature Chemical Bath Deposition of Conformal and Compact NiOX for Scalable and Efficient Perovskite Solar Modules.

A scalable and low-cost deposition of high-quality charge transport layers and photoactive perovskite layers are the grand challenges for large-area and efficient perovskite solar modules and tandem cells. An inverted structure with an inorganic hole transport layer is expected for long-term stability. Among various hole transport materials, nickel oxide has been investigated for highly efficient and stable perovskite solar cells. However, the reported deposition methods are either difficult for large-scale conformal deposition or require a high vacuum process. Chemical bath deposition is supposed to realize a uniform, conformal, and scalable coating by a solution process. However, the conventional chemical bath deposition requires a high annealing temperature of over 400 °C. In this work, an amino-alcohol ligand-based controllable release and deposition of NiOX using chemical bath deposition with a low calcining temperature of 270 °C is developed. The uniform and conformal in-situ growth precursive films can be adjusted by tuning the ligand structure. The inverted structured perovskite solar cells and large-area solar modules reached a champion PCE of 22.03% and 19.03%, respectively. This study paves an efficient, low-temperature, and scalable chemical bath deposition route for large-area NiOX thin films for the scalable fabrication of highly efficient perovskite solar modules.

Synergic effects of FeOOH and CoNi2Se4 bilayer nanosheets as highly efficient electrocatalysts for the oxygen evolution reaction

The substantial growth of nonprecious and inexpensive electrocatalysts for the oxygen evolution reaction (OER) is vital for commercial usage. In this work, cobalt nickel selenide (CoNi2Se4, called CNSe) thin film nanosheet heterojunctions with iron oxyhydroxide (FeOOH) thin film nanosheets were grown directly on a nickel foam substrate (Ni-foam) using an electrodeposition method. The electrocatalytic activity of CNSe/FeOOH bilayer nanosheets was evaluated for OER studies using its CNSe and FeOOH counterparts. The CNSe/FeOOH bilayer thin film exhibited a low overpotential of 222 mV to deliver a benchmark current density of 10 mA cm−2, which was lower than that of the CNSe (327 mV) and FeOOH (276 mV) electrocatalysts. The bilayer electrocatalyst delivered remarkable long-term electrochemical stability for more than 120 h at a constant current density of 10 mA cm−2. The excellent activity was attributed to the synergic effects of CNSe/FeOOH with high electrochemical active sites and feasible charge transfer ability. This study provides new insights for designing a different class of materials using a simple electrochemical deposition route for high-performance OER kinetics.

A Facile Aqueous Solution Route for the Growth of Chalcogenide Perovskite BaZrS3 Films

The prototypical chalcogenide perovskite, BaZrS3 (BZS), with its direct bandgap of 1.7–1.8 eV, high chemical stability, and strong light–matter interactions, has garnered significant interest over the past few years. So far, attempts to grow BaZrS3 films have been limited mainly to physical vapor deposition techniques. Here, we report the fabrication of BZS thin films via a facile aqueous solution route of polymer-assisted deposition (PAD), where the polymer-chelated cation precursor films were sulfurized in a mixed CS2 and Ar atmosphere. The formation of a single-phase polycrystalline BZS thin film at a processing temperature of 900 °C was confirmed by X-ray diffraction and Raman spectroscopy. The stoichiometry of the films was verified by Rutherford Backscattering spectrometry and energy-dispersive X-ray spectroscopy. The BZS films showed a photoluminescence peak at around 1.8 eV and exhibited a photogenerated current under light illumination at a wavelength of 530 nm. Temperature-dependent resistivity analysis revealed that the conduction of BaZrS3 films under the dark condition could be described by the Efros–Shklovskii variable range hopping model in the temperature range of 60–300 K, with an activation energy of about 44 meV.

Facile suspension flame spray fabrication of polylactic acid-povidone-iodine coatings for antimicrobial applications

A facile suspension flame deposition route for fabricating polylactic acid (PLA)-based antimicrobial coatings has been developed in this work. Mixture of povidone-iodine (PVP-I) solution and PLA particles was prepared as the starting feedstock to make the PLA-PVP-I composite coatings. Successful fabrication of the PLA-PVP-I coatings were confirmed by microstructure and chemistry analyses. The coatings showed a homogenous structure and smooth topographical features with no visible pores. Well retained chemistry of PLA and uniform dispersion of PVP-I was revealed in the coatings. Antibacterial testing showed remarkable antimicrobial activity of the PLA-PVP-I coatings against both Escherichia coli and Staphylococcus aureus with a bactericidal rate over 99.99 %, which is likely attributed to the rapid release of iodine. This study provides a promising substrate-independent thermal spray route for constructing antimicrobial coatings for potential biomedical applications.

Growth of ZnO/Ga2O3 and Ga2O3/ZnO heterostructures on c-Al2O3 substrate using pulsed laser deposition

Growth of ZnO/Ga2O3 and Ga2O3/ZnO heterostructures on c-Al2O3 substrate is demonstrated using pulsed laser deposition route. Based on the structural and surface morphological investigations hypothetical model explaining the respective growth is proposed. The template (i.e. Ga2O3/Al2O3 and ZnO/Al2O3) used to grow the final film are observed to control the overall micro structural, electrical as well as optical properties of these heterostructure. For e.g. broad UV emission is observed for Ga2O3 film deposited on the ZnO/Al2O3 substrate, whereas expected near band-edge emission is reported for ZnO film deposited on Ga2O3/Al2O3 substrate. Various emission processes involved in harvesting the UV-blue emission especially for Ga2O3/ZnO/Al2O3 heterostructure is explained by proposing the band diagram schematic.

Optical characteristics of chemically deposited MnSb2S4 thin films

In this research work, manganese antimony sulfide (MnSb2S4) films have been prepared and deposited via the chemical bath deposition route at various thicknesses (189, 275, 329, and 412 nm). The X-ray diffraction results confirmed the polycrystalline character of these films, which exposed orthorhombic structures. The compositional element percentages of these layers were analyzed via energy-dispersive X-ray spectroscopy. The impact of thickness on the optical characteristics of films has also been studied. The optical investigations manifest that these MnSb2S4 films demonstrate a direct optical transition with variable energy gap values (1.77–1.53 eV). The refractive index, optical dielectric constant, absorption coefficient, extinction coefficient, optical conductivity, and others have been estimated and studied. Additionally, the dispersion refractive index, dispersion, and oscillator energies of these spray-deposited films were computed and discussed. In the same way, increasing the thickness of the film has been shown to improve the nonlinear optical parameters. The hot-probe method using a negative voltage was used to investigate the semiconductor behaviour of MnSb2S4 films. It was found that these films tend to behave as p-type semiconductors. This study showed that MnSb2S4 films were utilized as a new absorber layer in photovoltaics.

Large-Area Growth of Two-Dimensional Rhenium Disulfide Depicting Robust Artificial Photoreceptor-cum-Optic Nerve Synaptic Functionality

The impact of artificial vision is surging all around, starting from automotive industries to neuromorphic computing, and it needs both software and hardware platforms. Despite massive progress through software-based simulations for artificial vision systems, hardware implementation still needs to catch up due to the material processing and device fabrication complexity. Here, we demonstrated a very simple two-terminal planar photodetector device to mimic functions of photoreceptors similar to the retina followed by potentiation of optic nerve synapse using a chemical vapor deposition (CVD)-grown two-dimensional rhenium disulfide (2D ReS2) monolayer film. First, large-area 2D ReS2 monolayer growth facilitated through organic seeding promoted the chemical vapor deposition route. The direct band gap of 1.5 eV and Peierls distorted 1T crystalline phase of ReS2 were identified from the Tauc plot analysis and transmission electron microscopy results. Then, the photodetection property and photoreceptor functionality were measured after depositing interdigitated palladium electrodes. Raman scattering and temporal photoresponse confirm that the oxide-interface-induced photogating effect plays a significant role in such functionalities. Photomodulated visual nervous system-related basic functions, including excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), and the simplest Atkinson–Shiffrin memory model, are verified efficiently even at elevated temperatures. Overall, this work can lead to an innovative research direction toward developing atomically thick photonic devices, which would be an innovative technology for artificial intelligence (AI), machine learning (ML), and optogenetics in the future.

Thickness dependent field emission study of LaB6 coated Si nanowire arrays

A simple physical metal mask is efficiently employed to obtain an array of silicon (Si) nanowires (Si-NWs) on a Si substrate grown using the hot filament chemical vapor deposition route. Well adhered and uniform coating of different thicknesses (20 and 50 nm) of lanthanum hexaboride (LaB6) on Si-NWs was obtained using electron beam evaporation technique. The thickness of LaB6 coating was estimated from ellipsometry measurement. Structural, morphological, and chemical properties of the LaB6 coated Si-NWs (LaB6@Si-NWs) arrays were revealed using x-ray diffraction, field emission scanning electron microscope, transmission electron microscope, Raman spectroscopy, and x-ray photoelectron spectroscopy. Field electron emission characteristics of pristine Si-NW array and LaB6 coated Si-NWs array emitters were studied in planar diode configuration at a base pressure of 1 × 10−8 mbar. The values of turn-on field (current density ∼1 μA/cm2) were observed as ∼2.2, 1.2, and 1.6 V/μm for pristine Si-NWs, LaB6@Si-NWs_20, and LaB6@Si-NWs_50 array emitters, respectively. Furthermore, maximum emission current densities of ∼1276.81, 2763.64, and 2231.81 μA/cm2 have been extracted from the pristine Si-NWs, LaB6@Si-NWS_20, and LaB6@Si-NWS_50 array emitters at an applied field of 3.1, 2.7, and 2.7 V/μm, respectively. The LaB6@Si-NWS_20 array emitter demonstrated superior FEE properties as compared to the pristine Si-NWs and LaB6@Si-NWS_50 emitters. Furthermore, LaB6@Si-NWS_20 emitter depicted very good emission current stability tested at a preset value of 1 μA over a duration of 3 h. The enhanced FEE performance exhibited by the LaB6@Si-NWs_20 array emitter is attributed to reduction in effective work function and enhanced electron tunneling probability across the LaB6–Si interface.

Facile Solid-State Synthesis of Supported PtNi and PtCo Bimetallic Nanoparticles for the Oxygen Reduction Reaction

Proton-exchange membrane fuel cells (PEMFCs) represent an essential technology for the future decarbonization of the transportation sector. A major component of PEMFCs is the catalyst, often Pt-based alloys supported on carbon black, which are sufficiently active and stable upon long-term operation under the harsh reaction conditions implied by PEMFCs. However, the catalyst synthesis is typically laborious and challenging to upscale, employing organic solvents, surfactants, or uneconomical metal deposition routes. To solve this, we offer a mechanochemically assisted two-step solvent-less methodology to produce supported metal catalysts, particularly supported PtNi and PtCo catalysts. Accordingly, metal salts are first dispersed on the designated support by planetary ball milling. Subsequently, the mixture is reduced with hydrogen and annealed under an inert atmosphere to yield supported alloyed nanoparticles. Notably, by applying our procedure to the synthesis of carbon-supported PtNi and PtCo nanoparticles, we demonstrate that size, composition, and total metal loading can be finely adjusted, leading to highly performant catalysts in the oxygen reduction reaction (ORR).

Engineering of NiO/ZnO Core-Shell Nanostructure via Facile Chemical Processes for Environmental Application

NiO/ZnO core–shell nanoflakes structures were successfully fabricated using a unique strategy consisting of a simple chemical bath deposition (CBD) route followed by a metal-organic chemical vapor deposition (MOCVD) technique with different growth times. The XRD results combined with Raman measurements and X-ray photoelectron spectroscopy confirmed that the surface property and photocatalytic activity of NiO/ZnO core–shell nanostructures affected by varying the growth time of ZnO on the surface of NiO nanoflakes. The Scanning electron microscopy images exhibited that the NiO/ZnO samples have a porous core–shell architecture with high surface area and abundant open sites, resulting in enhanced photocatalytic activity. The photocatalytic activity was tested for the prepared samples by measuring the degradation of crystal violet (CV) dye under ultraviolet irradiation. NiO/ZnO core–shell nanostructures deposited at 30 min exhibits higher photodegradation efficiency toward CV dye compared to NiO/ZnO core–shell deposited at 60 min and NiO nanoflakes standing alone. The enhanced photocatalytic activity is due to the formation of p–n heterojunction between ZnO and NiO with a high specific area and more active site of core–shell nanoflakes architecture. The obtained results in this research suggest a new strategy for the fabrication of highly efficient photocatalytic activity semiconducting metal oxide with core–shell.

Self-assembled fatty acid crystalline coatings display superhydrophobic antimicrobial properties.

Superhydrophobicity is a well-known wetting phenomenon found in numerous plants and insects. It is achieved by the combination of the surface's chemical properties and its surface roughness. Inspired by nature, numerous synthetic superhydrophobic surfaces have been developed for various applications. Designated surface coating is one of the fabrication routes to achieve the superhydrophobicity. Yet, many of these coatings, such as fluorine-based formulations, may pose severe health and environmental risks, limiting their applicability. Herein, we present a new family of superhydrophobic coatings comprised of natural saturated fatty acids, which are not only a part of our daily diet, but can be produced from renewable feedstock, providing a safe and sustainable alternative to the existing state-of-the-art. These crystalline coatings are readily fabricated via single-step deposition routes, namely thermal deposition or spray-coating. The fatty acids self-assemble into highly hierarchical crystalline structures exhibiting a water contact angle of ∼165° and contact angle hysteresis lower than 6°, while their properties and morphology depend on the specific fatty acid used as well as on the deposition technique. Moreover, the fatty acid coatings demonstrate excellent thermal stability. Importantly, this new family of coatings displays excellent anti-biofouling and antimicrobial properties against Escherichia coli and Listeria innocua, used as relevant model Gram-negative and Gram-positive bacteria, respectively. These multifunctional coatings hold immense potential for application in numerous fields, ranging from food safety to biomedicine, offering sustainable and safe solutions.

The microstructures and mechanical properties of Al-Zn-Mg-Cu-Si-Zr alloy: A comparison between directed energy deposition and laser powder bed fusion

Al–Zn–Mg–Cu-Si-Zr powders were manufactured by directed energy deposition (DED) and laser powder bed fusion (LPBF) routes, and their microstructures as well as mechanical behaviors were comparatively investigated. The sizes of pores and grains in the DED sample (30 and 15.36 μm) are way higher than that in the LPBF sample (3 and 3.12 μm). The microstructure of DED sample is composed of equiaxed grains, while the LPBF sample exhibits a mixed microstructure consisting of large columnar grains in the melt pool center and small equiaxed grains on the melt pool boundary. The mechanical properties of the LPBF sample are: Yield strength 356.9 MPa, tensile strength 451.8 MPa and elongation 5.50 %, which are way higher than the DED sample (Yield strength 238.8 MPa, tensile strength 305.8 MPa and elongation 2.80 %).