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Results for “B-Si”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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7 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Performance of black silicon photodiodes for VUV detection in noble liquids

Black silicon (b-Si) photodiodes are an emerging technology that employs silicon nanostructures to enhance the efficiency of photon detection. Recently, we demonstrated nearly 100% quantum efficiency at <200 nm vacuum ultraviolet (VUV) wavelengths at ambient and in noble liquids, making such devices particularly useful for direct detection of scintillation light in noble liquid detectors. This is important in nuclear science experiments like DarkSide, LUX, XENON, and nEXO, where detection of weak VUV scintillation photons in noble liquids are used to identify rare physics radiation events. Here, we measured the response of b-Si photodiode to the scintillation light generated by alpha particles, all immersed in a LAr and LXe test cell. We established a guideline for future development of b-Si photodetectors with internal gain to reach single-photon sensitivity.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

Ultradoping Boron on Si(100) via Solvothermal Chemistry

Ultradoping introduces unprecedented dopant levels into Si, which transforms its electronic behavior and enables its use as a next-generation electronic material. Commercialization of ultradoping is currently limited by gas-phase ultra-high vacuum requirements. Solvothermal chemistry is amenable to scale-up. However, an integral part of ultradoping is a direct chemical bond between dopants and Si, and solvothermal dopant-Si surface reactions are not well-developed. This work provides the first quantified demonstration of achieving ultradoping concentrations of boron (~1e14 cm 2 ) by using a solvothermal process. Surface characterizations indicate the catalyst cross-reacted, which led to multiple surface products and caused ambiguity in experimental confirmation of direct surface attachment. Density functional theory computations elucidate that the reaction results in direct B-Si surface bonds. Finally, this proof-of-principle work lays groundwork for emerging solvothermal ultradoping processes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on SiB3 by Materials Project

SiB3 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. there are four inequivalent B sites. In the first B site, B is bonded in a 6-coordinate geometry to five B and one Si atom. There are a spread of B–B bond distances ranging from 1.75–1.80 Å. The B–Si bond length is 1.98 Å. In the second B site, B is bonded in a 1-coordinate geometry to five B and one Si atom. There are a spread of B–B bond distances ranging from 1.77–1.85 Å. The B–Si bond length is 2.04 Å. In the third B site, B is bonded in a 6-coordinate geometry to six B atoms. There are a spread of B–B bond distances ranging from 1.72–1.93 Å. In the fourth B site, B is bonded in a 6-coordinate geometry to five B and one Si atom. The B–Si bond length is 2.01 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 2-coordinate geometry to two equivalent B and three Si atoms. There are one shorter (2.34 Å) and two longer (2.59 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a distorted bent 120 degrees geometry to two B and two equivalent Si atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SiB6 by Materials Project

SiB6 is Calcium hexaboride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional and consists of one silicon molecule and one B framework. In the B framework, B is bonded in a 5-coordinate geometry to five equivalent B atoms. There is one shorter (1.65 Å) and four longer (1.75 Å) B–B bond length.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Si3B by Materials Project

BSi3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. B is bonded to twelve equivalent Si atoms to form BSi12 cuboctahedra that share corners with six equivalent BSi12 cuboctahedra, corners with twelve equivalent SiSi8B4 cuboctahedra, edges with eighteen equivalent SiSi8B4 cuboctahedra, faces with eight equivalent BSi12 cuboctahedra, and faces with twelve equivalent SiSi8B4 cuboctahedra. There are six shorter (2.51 Å) and six longer (2.64 Å) B–Si bond lengths. Si is bonded to four equivalent B and eight equivalent Si atoms to form distorted SiSi8B4 cuboctahedra that share corners with four equivalent BSi12 cuboctahedra, corners with fourteen equivalent SiSi8B4 cuboctahedra, edges with six equivalent BSi12 cuboctahedra, edges with twelve equivalent SiSi8B4 cuboctahedra, faces with four equivalent BSi12 cuboctahedra, and faces with sixteen equivalent SiSi8B4 cuboctahedra. There are a spread of Si–Si bond distances ranging from 2.47–2.67 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SiB by Materials Project

BSi is Wurtzite structured and crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. B is bonded to four equivalent Si atoms to form corner-sharing BSi4 tetrahedra. There are one shorter (1.99 Å) and three longer (2.06 Å) B–Si bond lengths. Si is bonded to four equivalent B atoms to form corner-sharing SiB4 tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SiB4 by Materials Project

SiB4 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent B sites. In the first B site, B is bonded in a 1-coordinate geometry to five B and two Si atoms. There are a spread of B–B bond distances ranging from 1.75–1.86 Å. There are one shorter (2.01 Å) and one longer (2.63 Å) B–Si bond lengths. In the second B site, B is bonded in a 6-coordinate geometry to six B atoms. There is one shorter (1.85 Å) and two longer (1.92 Å) B–B bond length. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 4-coordinate geometry to three equivalent B and one Si atom. The Si–Si bond length is 2.17 Å. In the second Si site, Si is bonded in a 2-coordinate geometry to six equivalent B and two equivalent Si atoms.

36 MATERIALS SCIENCE↗