CVD Synthesis and Thermoelectric Properties of Boron Carbide

Koumoto, Kunihito; Seki, Takao; Pai, Chul Hoon; Yanagida, Hiroaki

doi:10.2109/jcersj.100.853

Cited by 12 publications

(4 citation statements)

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“…However, the Hall coefficients for the films could not be obtained possibly because of their amorphous nature. B x C exhibits positive Seebeck coefficients, where x varies from ∼4 to ∼11, 63) confirming that it is a p-type semiconductor.…”

Section: Resultsmentioning

confidence: 81%

Photovoltaic and mechanical properties of boron carbide films prepared by magnetron sputtering

Nishida,

Sato,

Enta

et al. 2024

Jpn. J. Appl. Phys.

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In this study, amorphous boron carbide (BxC) and hydrogenated amorphous BxC (BxC:H) films were deposited via magnetron sputtering to investigate the effects of hydrogen on the film properties. The critical load decreased with increasing H2 flow ratio, probably due to an increase in the internal stress. In addition, the optical bandgap increased with the H2 flow ratio increased. The bandgap was controlled by the chemical bonding of carbon atoms and the chemical composition of films. The resistivity of the films increased with the H2 flow ratio and bandgap energy. The current–voltage characteristics of BxC(:H)/n-type Si heterojunctions under white light illumination showed that the short-circuit current density and open-circuit voltage were higher than the previously reported values. Results revealed that the introduction of hydrogen during deposition reduced the short-circuit current density, fill factor, and conversion efficiency, whereas the open-circuit voltage remained almost unchanged.

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Section: Resultsmentioning

confidence: 81%

Photovoltaic and mechanical properties of boron carbide films prepared by magnetron sputtering

Nishida,

Sato,

Enta

et al. 2024

Jpn. J. Appl. Phys.

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“…Among the above methods, the synthesis using constituent elements is not cost-effective due to the expensive pure raw materials required and is merely a research-based methodology for synthesis in the laboratory [23]. The CVD method, despite its advantages such as very high purity of the final product and the ability to precisely control the size and amount of materials in the composition of solid B4C, due to the high cost of needed equipment and low production volume at each run of synthesis process, cannot be used as a universally accepted industrial route [24,25]. Among other methods, the carbothermal reduction is a relatively easier and less expensive technique in terms of materials and equipment required, but the main drawback of this method is the need of ultrahigh temperatures for the synthesis of B4C.…”

Section: Introductionmentioning

confidence: 99%

Performance of glucose, sucrose and cellulose as carbonaceous precursors for the synthesis of B4C powders

et al. 2022

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Boron carbide is the third hardest material in the world after diamond and cubic boron nitride, which is one of the most strategic engineering ceramics in various industrial applications. The aim of this research is to synthesize B4C by reacting boric acid as boron source with polymers from the saccharide family as carbon sources, and to determine the best saccharide as precursor. For this purpose, glucose (monosaccharide), sucrose (disaccharide), and cellulose (polysaccharide) were used and examined. The samples were prepared by appropriate mixing of the starting materials, pyrolysis at 700 °C, and synthesis at 1500 °C. The results of Fourier transform infrared (FT-IR) spectroscopy and X-ray diffractometry (XRD) showed that among the studied saccharide polymers, glucose is the best carbon source candidate for the synthesis of B4C. To describe precisely, the specimen prepared with glucose and boric acid had more boron carbide and less hydrocarbon.

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“…However, brittleness of ceramics is an important problem that must be solved for structural material. On the other hand, recently B4C has been much interested due to its high thermoelectric properties [2,3].…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Synthesis and Densification of Carbon Nano-Materials Dispersed Boron Carbide Composites Using Pulsed Electric-Current Pressure Sintering (PECPS)

Hirota

Hirahara

Kato

et al. 2020

MSF

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Dense [boron carbide (B4C)]/[carbon nanomaterials] composites were synthesized and sintered simultaneously using pulsed electric-current pressure sintering (PECPS) at 2173 K for 6.0×102 s (10 min) under 50 MPa in a vacuum. The starting powders were amorphous B and C nanopowders and nanocarbons. The latter were acid-treated carbon nanofiber CNF and carbon nanotube CNT. The sintered composites were evaluated from the viewpoints of mechanical properties at high temperatures up to ~ 2023 K in inert atmosphere. Thus fabricated composites with 10vol%CNF maintained high bending strength σb around 750 MPa even at 1973 K; this temperature is 100 K higher than that of conventional B4C/CNF composites, and furthermore 600 MPa at 2023 K. These high σb at elevated temperatures might be explained by both the low content of catalytic Fe particles and the rough surface of CNF after the acid-treatment. On the other hand, B4C/CNT composites displayed 770 MPa at 1723 K. The stress-strain curves demonstrate that B4C/CNF composite deformed elastically until 1273 K and plastically up to 1973 K, however, the B4C/CNT composites displayed elastic deformation up to around 1873 K.

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CVD Synthesis and Thermoelectric Properties of Boron Carbide

Cited by 12 publications

References 0 publications

Photovoltaic and mechanical properties of boron carbide films prepared by magnetron sputtering

Photovoltaic and mechanical properties of boron carbide films prepared by magnetron sputtering

Performance of glucose, sucrose and cellulose as carbonaceous precursors for the synthesis of B4C powders

Simultaneous Synthesis and Densification of Carbon Nano-Materials Dispersed Boron Carbide Composites Using Pulsed Electric-Current Pressure Sintering (PECPS)

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