Boron Doping Research Articles

Boron Doping: Unlocking Arsenic-Mimicking Performance in GeSe-Based OTS Selectors

Boron Doping: Unlocking Arsenic-Mimicking Performance in GeSe-Based OTS Selectors

Synthesis and investigation of novel boron- and magnesium-doped YAG:Ce and LuAG:Ce phosphor ceramics.

YAG:Ce and LuAG:Ce ceramics are widely used as scintillator materials that convert high-energy radiation into visible light. For the practical application of such compounds, short decay times are a necessity. One way of shortening the existing decay times even more is to change the local environment of emitting ions by means of doping the matrix with additional elements, for example, boron or magnesium. Furthermore, boron ions also can help absorb gamma rays more efficiently, therefore improving overall applicability. Due to the aforementioned reasons, YAG and LuAG ceramics doped with cerium, boron, and magnesium were synthesized. Initial amorphous powders have been obtained by means of sol-gel synthesis and pressed into pellets under isostatic pressure and finally calcinated to form crystalline ceramics. The effects of boron and magnesium doping on the morphological, structural, and luminescence properties were investigated. The key results showed that doping with boron has indeed shortened the decay times of the garnet pellets. Overall, boron doping of ceramics is a relatively new research area; however, it is rather promising as it helps both to improve the luminescence properties and to increase particle growth rate.

Theoretical prediction of C- and O-doped Hittorf’s violet phosphorene as bipolar magnetic semiconductor material

Hittorf’s violet phosphorene is a novel two-dimensional material with stable structure and excellent optoelectronic properties. Studying the doping effect helps to understand its physical essence and is of great significance in further developing nanoelectronic devices. In this paper, the first-principles method based on density functional theory is used to study the electromagnetic properties of the non-metallic element B-, C-, N-, and O-doped single-layer violet phosphene. The results show that there is no magnetism after having doped boron and nitrogen, and the system still behaves as a nonmagnetic semiconductor, while carbon doping and oxygen doping cause spin splitting, and the violet phosphorene transforms from a nonmagnetic semiconductor to a bipolar magnetic semiconductor, and its spin density is mainly distributed in the P atom and gap region, rather than on the impurity. The direction of spin polarization of its carrier can be reversed by adjusting the electric field of O-doped violet phosphorene. When a certain size of forward or reverse electrostatic field is applied, the band dispersion becomes stronger, and the O-doped violet phosphorene transforms into a half-metallic magnet with 100% downward or upward spin polarization at the Fermi level. The field effect spin filter based on O-doped violet phosphorene can reverse the direction of spin-polarized current by changing the direction of the gate voltage. This study shows that O-doped violet phosphorene is expected to be an ideal candidate material for two-dimensional spin field-effect transistors, bipolar magnetic spintronic devices, dual channel field effect spin filters, and field-effect spin valves.

Gold and silver: Noble solvents for the synthesis of superconducting boron-doped diamonds

The synthesis of diamonds in traditional growth systems based on Fe, Co and Ni does not allow overcoming the semiconductor level of boron doping of diamond, presumably because of a high affinity of boron to boride-forming metals. For the first time, noble metals that do not form borides—silver and gold—are used as growth media for the synthesis of heavily boron-doped diamonds at 8–9 GPa. Gold and silver are not catalysts for the transformation of graphite to diamond, whereas elemental boron is catalytically active at eutectic melting temperatures above 2500 K. It is found that the synthesis of diamond in AgB and AuB growth media starts at temperatures close to the melting temperatures of Ag and Au, 1600 and 1800 K, respectively. Calculations show that molten Au and Ag dissolve boron atoms without a significant change in the electronic structure of the solution, suggesting that the metal melts serve as a carrier for the boron catalyst. The resulting polycrystalline diamond contains dispersed inclusions of Ag and Au, as well as traces of boron carbide; the formation of borides is not detected. The transport measurements of the diamond samples reveal a transition to a superconducting state in the temperature range from 4.5 to 2.5 K. Raman spectroscopy confirms the heavy boron doping of diamond. Thus, we show that melts of “non-catalytic” metals that do not form borides can be effectively used to synthesize boron-doped conductive/superconducting diamonds at relatively low temperatures.

Electron-deficient sites on boron-doped graphite enable air-stable and durable red phosphorus anode for lithium-ion batteries

Electron-deficient boron doping into graphite can enhance the chemical affinity to electron-rich RP via strong P–C bonds, which can maintain the structural stability and effective electrical contact between them during long-term cycling processes.

Tuning nitrogen species in 3D porous carbon via boron doping for boosted Zn-ion storage capability

A strategy for the conversion of graphitic-N to edge-N in a carbon matrix by the additional incorporation of boron element for zinc-ion hybrid supercapacitor cathodes.

Preparation of a lithium-sulfur battery diaphragm catalyst and its battery performance.

Lithium-sulfur batteries (LSBs) with metal lithium as the anode and elemental sulfur as the cathode active materials have attracted extensive attention due to their high theoretical specific capacity (1675 mA h g-1), high theoretical energy density (2600 W h kg-1), low cost, and environmental friendliness. However, the discharge intermediate lithium polysulfide undergoes a shuttle side reaction between the two electrodes, resulting in low utilization of the active substances. This limits the capacity and cycle life of LSBs and further delays their commercial development. However, the number of active sites and electron transport capacity of such catalysts still do not meet the practical development needs of lithium-sulfur batteries. In view of these issues, this paper focuses on a zinc-cobalt compound catalyst, modifying it through heteroatom doping, bimetallic synergistic effect and heterogeneous structure design to enhance the performance of LSBs as a separator modification material. A carbon shell-supported boron-doped ZnS/CoS2 heterojunction catalytic material (B-ZnS/CoS2@CS) was prepared, and its performance in lithium-sulfur batteries was evaluated. A carbon substrate (CS) was prepared by pyrolysis of sodium citrate, and the boron-doped ZnS/CoS2 heterojunction catalyst was formed on the CS using a one-step solvothermal method. The unique heterogeneous interface provides numerous active sites for the adsorption and catalysis of polysulfides. The uniformly doped, electron-deficient boron further enhances the Lewis acidity of the ZnS/CoS2 heterojunction, while also regulating electron transport. The B-ZnS/CoS2@CS catalyst effectively inhibits the diffusion of LiPS anions by utilizing additional lone-pair electrons. The lithium-sulfur battery using the catalyst-modified separator achieves a high specific capacity of 1241 mA h g-1 at a current density of 0.2C and retains a specific capacity of 384.2 mA h g-1 at 6.0C. In summary, B-ZnS/CoS2@CS heterojunction catalysts were prepared through boron doping modification. They can promote the conversion of polysulfides and effectively inhibit the shuttle effect. The findings provide valuable insights for the future modification and preparation of lithium-sulfur battery catalysts.

A porous network of boron-doped IrO2 nanoneedles with enhanced mass activity for acidic oxygen evolution reactions.

While proton exchange membrane water electrolyzers (PEMWEs) are essential for realizing practical hydrogen production, the trade-off among activity, stability, and cost of state-of-the-art iridium (Ir)-based oxygen evolution reaction (OER) electrocatalysts for PEMWE implementation is still prohibitively challenging. Ir minimization coupled with mass activity improvement of Ir-based catalysts is a promising strategy to address this challenge. Here, we present a discovery demonstrating that boron doping facilitates the one-dimensional (1D) anisotropic growth of IrO2 crystals, as supported by both experimental and theoretical evidence. The synthesized porous network of ultralong boron-doped iridium oxide (B-IrO2) nanoneedles exhibits improved electronic conductivity and reduced charge transfer resistance, thereby increasing the number of active sites. As a result, B-IrO2 displays an ultrahigh OER mass activity of 3656.3 A gIr-1 with an Ir loading of 0.08 mgIr cm-2, which is 4.02 and 6.18 times higher than those of the un-doped IrO2 nanoneedle network (L-IrO2) and Adams IrO2 nanoparticles (A-IrO2), respectively. Density functional theory (DFT) calculations reveal that the B doping moderately increases the d-band center energy level and significantly lowers the free energy barrier for the conversion of *O to *OOH, thereby improving the intrinsic activity. On the other hand, the stability of B-IrO2 can be synchronously promoted, primarily attributed to the B-induced strengthening of the Ir bonds, which help resist electrochemical dissolution. More importantly, when the B-IrO2 catalysts are applied to the membrane electrode assembly for PEM water electrolysis (PEMWE), they generate a remarkable current density of up to 2.8 A cm-2 and maintain operation for at least 160 h at a current density of 1.0 A cm-2. This work provides new insights into promoting intrinsic activity and stability while minimizing the usage of noble-metal-based OER electrocatalysts for critical energy conversion and storage.

Core-shells particles grown in a tubular reactor: Influence of the seeds nature and MPCVD conditions on boron-doped diamond crystalline quality

A trend in the synthesis of Boron Doped Diamond (BDD) materials resides in increasing surface areas to exalt reactivity at the BDD/electrolyte interface. This can be achieved either by surface structuration of BDD films or conformal growth on 3D substrates. Another strategy considers isolated BDD particles, mainly obtained by milling of BDD layers that can be further deposited on surfaces or embedded in a conductive matrix. Here, we propose an alternative method to obtain boron-doped diamond particles using a core-shell approach, which consists in growing diamond coatings on spherical silica templates seeded with nanodiamonds. We investigated the effects of the nature and the density of diamond seeds as well as growth parameters on the crystalline quality of the coatings. The microstructure and the boron incorporation in the diamond shell was investigated by combining Scanning Electron Microscopy (SEM), UV Raman and X-ray Photoemission Spectroscopy (XPS) investigations. Such characterizations were compared to Scanning TEM (STEM) imaging, Energy Dispersive Spectroscopy (EDS) and Electron energy loss spectroscopy (EELS) performed on thin cross-sections of core-shells prepared by focused ion beam (FIB) milling.

The impact of boron doping in the tunneling magnetoresistance of Heusler alloy Co2FeAl

Heusler alloy-based magnetic tunnel junctions have the potential to provide high spin polarization, small damping, and fast switching. In this study, junctions with a ferromagnetic electrode of Co2FeAl were fabricated via room-temperature sputtering on Si/SiO2 substrates. The effect of boron doping on Co2FeAl magnetic tunnel junctions was investigated for different boron concentrations. The surface roughness determined by atomic force microscope, and the analysis of x-ray diffraction measurement on the Co2FeAl thin film reveals critical information about the interface. The Co2FeAl layer was deposited on the bottom and on the top of the insulating MgO layer as two different sample structures to compare the impact of the boron doping on different layers through tunneling magnetoresistance measurements. The doping of boron in Co2FeAl had a large positive impact on the structural and magneto-transport properties of the junctions, with reduced interfacial roughness and substantial improvement in tunneling magnetoresistance. In samples annealed at low temperature, a two-level magnetoresistance was also observed. This is believed to be related to the memristive effect of the tunnel barrier. The findings of this study have practical uses for the design and fabrication of magnetic tunnel junctions with improved magneto-transport properties.

Microwave-assisted exploration of the electron configuration-dependent electrocatalytic urea oxidation activity of 2D porous NiCo2O4 spinel

Urea holds promise as an alternative water-oxidation substrate in electrolytic cells. High-valence nickel-based spinel, especially after heteroatom doping, excels in urea oxidation reactions (UOR). However, traditional spinel synthesis methods with prolonged high-temperature reactions lack kinetic precision, hindering the balance between controlled doping and highly active two-dimensional (2D) porous structures design. This significantly impedes the identification of electron configuration-dependent active sites in doped 2D nickel-based spinels. Herein, we present a microwave shock method for the preparation of 2D porous NiCo2O4 spinel. Utilizing the transient on-off property of microwave pulses for precise heteroatom doping and 2D porous structural design, non-metal doping (boron, phosphorus, and sulfur) with distinct extranuclear electron disparities serves as straightforward examples for investigation. Precise tuning of lattice parameter reveals the impact of covalent bond strength on NiCo2O4 structural stability. The introduced defect levels induce unpaired d-electrons in transition metals, enhancing the adsorption of electron-donating amino groups in urea molecules. Simultaneously, Bode plots confirm the impact mechanism of rapid electron migration caused by reduced band gaps on UOR activity. The prepared phosphorus-doped 2D porous NiCo2O4, with optimal electron configuration control, outperforms most reported spinels. This controlled modification strategy advances understanding theoretical structure-activity mechanisms of high-performance 2D spinels in UOR.

Tuning microstructures of polyacrylonitrile-based carbon fibers by catalytic influence of boron for enhancement of mechanical properties and oxidation resistance

Boron catalytic graphitization of carbon fibers (CFs) is an effective methodology for reducing energy costs with the enhancement of tensile and oxidation resistance properties by re-constructing the crystal structure of CFs. Herein, a microwave plasma graphitization system for boron catalytic graphitization was devised. The effect of boron on microstructure and properties of CFs during boron catalytic graphitization process was investigated and analyzed. The mechanism of boron doping in different graphitization times was proposed. Furthermore, the results show that the tensile properties and oxidation resistance of CFs are improved and directly related to the microstructure of CFs, which depends on the different boron catalytic graphitization stages. This work provides the effect of boron on microstructure and properties of CFs during microwave plasma catalytic graphitization in different graphitization times and has important implications for deeply understanding the boron catalytic graphitization process which is beneficial for the preparation of CFs with excellent performance.

Microstructure- and Surface-Modified Ni-Rich Layered Cathode for High-Energy All-Solid-State Batteries

Li-ion batteries, which have been widely commercialized in the portable electronic devices and electric vehicles, pose a potential safety risk because the flammable liquid electrolyte can cause explosions under certain conditions. All-solid-state batteries (ASSBs) are promising candidates due to the potentially improved safety as well as high energy density. However, realizing high energy density ASSBs by employing Ni-rich layered cathode is difficult because of the microcrack with detrimental volume contraction near charge end as well as side reaction with solid electrolytes (SE). To overcome these limitations, this study show that the simultaneous boron doping and coating of a Ni-rich Li[Ni0.9Co0.05Mn0.05]O2 (NCM90) cathode, which modifies the cathode microstructure and protects cathode-SE interface, respectively, afford an ASSB that demonstrates an initial discharge capacity of 214 mAh g-1 and cycles stably 300 cycles with minimal capacity fading. The proposed dual treatment of the NCM90 cathode offers a viable approach to realizing a high energy density ASSBs with long cycle life by fracture-toughening the Ni-rich cathode and constructing a mechanically and chemically robust cathode-SE interface.

(Invited) Polymeric Carbon Nitride for Photocatalytic Overall Water Splitting

Photocatalytic overall water splitting can be achieved using Z-scheme systems that mimic natural photosynthesis by combining dissimilar semiconductors in series. However, coupling well-suited H2- and O2-evolving components remains challenging. Here, we fabricate a Z-scheme system for photocatalytic overall water splitting based on boron-doped, nitrogen-deficient carbon nitride two-dimensional (2D) nanosheets. We prepare ultrathin carbon nitride nanosheets with varying levels of boron dopants and nitrogen defects, which leads to nanosheets that can act as either H2- or O2-evolving photocatalysts. Using an electrostatic self-assembly strategy, the nanosheets are coupled to obtain a 2D/2D polymeric heterostructure. Owing to their ultrathin nanostructures, strong interfacial interaction and staggered band alignment, a Z-scheme route for efficient charge-carrier separation and transfer is realized. The obtained heterostructure achieves stoichiometric H2 and O2 evolution in the presence of Pt and Co(OH)2 co-catalysts, and the solar-to-hydrogen efficiency reaches 1.16% under one-sun illumination.

Study on selective emitter fabrication through an innovative pre‐diffusion process for enhanced efficiency in TOPCon solar cells

AbstractTOPCon (tunnel oxide passivated contact) solar cell is the mainstream high‐efficiency crystalline silicon solar cell structure. However, the lack of efficient passivation contact mechanisms on the front surface restricts the electrical performance ability to improve further. Selective emitter (SE) technology, considered a potential solution, needs to be more mature. This work provides a unique thermal pre‐diffusion approach combined with laser treatment and post‐oxidation annealing to create SE structures in TOPCon solar cells. Times for the high‐temperature process are equivalent to those for a traditional homogenous emitter. The innovative thermal pre‐diffusion process created a unique boron doping profile, achieving a high surface concentration of nearly 1 × 1020 cm−3 with a shallow junction depth of approximately 0.25 μm. Laser treatment further activated boron and facilitated its diffusion, influenced by the boron silicate glass layer and surface boron atoms. Adjustments were made to improve the pre‐diffusion recipe, including an additional boron deposition step, increasing non‐activated boron atoms. Introducing larger pyramidal microstructures also improved the junction depth and surface concentration in the heavily doped region. Compared to homogeneous emitters, the SE structures exhibited lower surface concentration in the lightly doped region, reducing the recombination current density in the passivation region J0,pass values. The SE structures achieved higher junction depths, limiting metal atom diffusion and reducing the current recombination density in the metal contact region J0,metal values. The contact resistivity between metal and silicon was also decreased. Overall, introducing SE structures resulted in a batch‐average efficiency improvement of 0.26%, reaching an average efficiency of 25.22% for TOPCon solar cells, and has industrial mass‐producible.

Enhancing non-radical peroxydisulfate activation by single-atom Fe-N-C catalyst through boron doping

Atomically dispersed transition metal-nitrogen-carbon (M-N-C) is regarded as one of the prospective materials to eliminate organic pollutants in water. However, manipulating the coordination sphere of the center metal to achieve the highest catalytic performance remains a challenge. Herein, a Fe-BNC catalyst with Fe atom decorated B,N-codoped hierarchical porous carbon was synthesized for peroxydisulfate (PDS) activation, which exhibits superb and highly selective degradation of model aqueous pollutants within a wide pH scope (2.63–10.36). The experiments and theoretical simulation indicate that the high activity of Fe-BNC origins from novel dual-pathway activation, involving PDS oxidation at the electron-poor B atoms for the formation of singlet oxygen (1O2) and PDS reduction over electron-rich Fe atoms for the generation of hydroxyl and sulfate radicals, where 1O2 was the primary active species. Moreover, the B atoms introduces point defects and optimizes the distribution of Fe 3d orbitals, which simultaneously facilitates PDS chemical adsorption and activation. We further loaded Fe-BNC on the widely used polyvinylidene fluoride (PVDF) microfiltration membrane and proved the stable performance for removing model pollutants when they pass through the filter, advancing the applications of M-N-C materials in actual practice.

Growth mechanism and field emission of B doped AlN films

This paper highlights the effect of boron dopant on the field emission and growth mechanism of AlN films. The films have been grown by reactive RF magnetron sputtering method. For undoped films, columnar AlN structure was obtained. In the case of boron doped AlN films, the structure growth proceeded gradually through four layers of different thicknesses and structures. It was found that boron favors the formation of an amorphous layer within which oxygen and boron based precipitates develops, retarding the growth of columnar morphology. Depth profiling X-ray photoelectron spectroscopy analyses confirm the presence of B-O, B-N, Al-B and Al-O groups.The study on the field emission (FE) properties of undoped and B doped AlN films on Si substrates indicates that the addition of boron allow to improve FE properties with low turn on field of 2.6 V/μm and low threshold filed of 3.07 V/μm. Such good field emission properties can be attributed to the formation of densely nanograined surface and the appearance of boron based groups.

First-principles investigation of Boron-doped graphene/MoS2 heterostructure as a potential anode material for Mg-ion battery

In this work, the potential of boron-doped graphene/MoS2 (Gr/MoS2) as an anode material for magnesium ion batteries was investigated using density functional theory (DFT) based on first-principles calculations. It’s found that the adsorption capacity gradually increases (−3.078 eV) with the increase in the number of doped-boron atom. Due to the lower electronegativity of boron atom (2.04) compared to carbon atom (2.55), electrons can be transferred from boron atom to neighboring carbon atoms, resulting in positively charged boron atom. Boron doping introduces p-type doping, which increases the number of holes in the substrate and raises the carrier concentration. The energy of the density of states near the Fermi level also increases with the increase of boron-doping concentration, indicating its excellent electronic conductivity. When the number of boron atoms reaches four, the barriers of the two diffusion paths reduce to 0.49 eV and 1.025 eV, respectively. Simultaneously, the theoretical magnesium storage capacity increases to 147.26 mAh g−1. Our research results demonstrate that boron-doping significantly enhances the adsorption and storage performance of Mg, providing a theoretical basis for the investigation of anode materials for magnesium ion batteries.

Revealing the structure of SiO2 and its effects on electrical properties

In this paper, the effects of vacancies and dopants on α-SiO2 are fully investigated with the first principle calculation and the finite element analysis method. The vacancies and dopants including the oxygen vacancy, silicon vacancy, boron dopant, and phosphorous dopant are considered. The oxygen vacancy, P substituted with O, and Si substituted with B are the most stable in the process of the oxide growth leading to the multi-layer microstructure of the tunneling oxide on the silicon substrate, and their concentrations increase with the temperature. Si substituted with B has larger capture cross sections than the other two types. The SONOS FLASH structure is built with the realistic manufacturing process to clarify the electrical effect of the multi-layer. The programming process with introduced levels from vacancies and dopants will be weakened with less charges storing in the floating gate which can reduce the circuit performance. The theoretical study from the electronic structure to electrical properties has remarkable senses for manufacturing devices and improving device performance in the future.

Preparation of a new B-CNTs/PSSF composite catalyst for catalytic wet peroxide oxidation of phenol in structured fixed bed

A new structured catalyst consisting of boron-doped carbon nanotubes growing directly on paper-like stainless steel fibers support (B-CNTs/PSSF) was developed for continuous catalytic wet peroxide oxidation (CWPO) of phenol in a structured fixed bed. Firstly, B-CNTs/PSSF was synthesized by chemical vapor deposition (CVD) with phenyboronic acid as a single precursor and CNTs/PSSF was prepared with camphor for comparison. Secondly, the effects of different deposition temperatures, deposition times, and phenylboronic acid dosages on the morphology and properties of B-CNTs were investigated, respectively. The results verified that under the conditions of deposition temperature of 750 °C, deposition time of 20 min, and phenylboronic acid dosage of 2 g, the B-CNTs/PSSF composite catalyst with uniform growth density, wavy and kinked morphology, abundant oxygen-containing functional groups and defect sites, and boron-doped content of 2.96% was successfully prepared. Then, the performance of B-CNTs/PSSF for continuous CWPO of phenol was evaluated. Catalytic results revealed that the B-CNTs/PSSF showed excellent catalytic activity in phenol degradation within 7 h (phenol conversion reached about 100% and total organic carbon (TOC) conversion was up to 68%). In contrast, the average phenol and TOC conversion of CNTs/PSSF were about 75% and 35%, respectively. It indicated that boron doping endowed CNTs with higher catalytic activity.