Polymer-derived SiBCN ceramic pressure sensor with excellent sensing performance

2020

Preprint

The amorphous and heterogeneous microstructures of polymer-derived ceramics (PDCs) make it challenging to uniformly polish them without the appearance of obvious polishing defects. In this study, the surface characteristics of polymer-derived silicoaluminum carbonitride (SiAlCN) ceramics were investigated after mechanical polishing and chemical–mechanical polishing (CMP). The results showed the generation of polishing defects including scratches, pits, and comet tails after mechanical polishing; nonetheless, the surface quality was largely improved after CMP, providing an ultra-smooth surface (Ra = ~0.25 nm). The evolution of the surface morphology was characterized in detail and X-ray photoelectron spectroscopy was used to analyze the characteristics of chemical bond before and after the CMP. The polishing slurry dominated the corrosion process during CMP, inducing the oxidation of the SiCxNy phase; nonetheless, the so-formed oxidation products and carbon phase were removed by mechanical action. The obtained ultra-high smooth surface can promote practical application in the field of PDCs-based sensors.

Section: Introductionmentioning

confidence: 99%

WITHDRAWN: Ultra-Precision Polishing Method of Polymer-Derived Amorphous SiAlCN Ceramics

Chen

Cao

2020

Preprint

“…This pressure-induced variation of band gap indicates that the β-SnO might be used as a pressure sensor [46].…”

Section: The Electronic Properties Under External Pressurementioning

confidence: 85%

Crystal and Electronic Structure Engineering of Tin Monoxide by External Pressure

Блатов

et al. 2020

Preprint

Although tin monoxide (SnO) is an interesting compound due to its p-type conductivity, a widespread application of SnO has been limited by its narrow band gap of 0.7 eV. In this work, we theoretically investigate the structural and electronic properties of several SnO phases under high pressure through employing van der Waals (vdW) functionals. Our calculations reveal that a metastable SnO (A-SnO), which possesses space group P21/c and a wide band gap of 1.9 eV, is more stable than l-SnO at pressures higher than 80 GPa. Moreover, a stable (space group P2/c) and a metastable (space group Pnma) phases of SnO appear at pressures higher than 120 GPa. Energy and topological analyses show that P2/c-SnO has a high possibility to directly transform to t-SnO at around 120 GPa. Our work also reveals that h-SnO is a necessary intermediate state between high-pressure phase Pnma-SnO and low-pressure phase o-SnO for the phase transition path Pnma-SnO ®u-SnO ® g-SnO. Two phase transition analyses indicate that there is a high possibility to synthesize h-SnO under high-pressure conditions and have it remain stable under normal pressure. Finally, our study reveals that the conductive property of -SnO can be engineered in a low-pressure range (0-9 GPa) through a semiconductor-to-metal transition, while maintaining transparency in the visible light range.

“…S9 in the ESM). This pressure-induced variation of band gap indicates that the -SnO might be used as a pressure sensor [49]. The analysis of hole and electron effective mass demonstrates that pressure may alter the conductive property of -SnO (Fig.…”

Section: Electronic Properties Under External Pressurementioning

confidence: 91%

Crystal and electronic structure engineering of tin monoxide by external pressure

Блатов

et al. 2021

J Adv Ceram

Although tin monoxide (SnO) is an interesting compound due to its p-type conductivity, a widespread application of SnO has been limited by its narrow band gap of 0.7 eV. In this work, we theoretically investigate the structural and electronic properties of several SnO phases under high pressures through employing van der Waals (vdW) functionals. Our calculations reveal that a metastable SnO (β-SnO), which possesses space group P21/c and a wide band gap of 1.9 eV, is more stable than α-SnO at pressures higher than 80 GPa. Moreover, a stable (space group P2/c) and a metastable (space group Pnma) phases of SnO appear at pressures higher than 120 GPa. Energy and topological analyses show that P2/c-SnO has a high possibility to directly transform to β-SnO at around 120 GPa. Our work also reveals that β-SnO is a necessary intermediate state between high-pressure phase Pnma-SnO and low-pressure phase α-SnO for the phase transition path Pnma-SnO →β-SnO → α-SnO. Two phase transition analyses indicate that there is a high possibility to synthesize β-SnO under high-pressure conditions and have it remain stable under normal pressure. Finally, our study reveals that the conductive property of β-SnO can be engineered in a low-pressure range (0–9 GPa) through a semiconductor-to-metal transition, while maintaining transparency in the visible light range.