Evolution of the Adsorbed Water Layer Structure on Silicon Oxide at Room Temperature

2005 ◽  
Vol 109 (35) ◽  
pp. 16760-16763 ◽  
Author(s):  
David B. Asay ◽  
Seong H. Kim
Keyword(s):  
Room Temperature ◽  
Silicon Oxide ◽  
Layer Structure ◽  
Water Layer ◽  
Adsorbed Water

scholarly journals Effect of Humidity on Friction and Wear—A Critical Review

Lubricants ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 74 ◽  
Author(s):  
Zhe Chen ◽  
Xin He ◽  
Chen Xiao ◽  
Seong Kim
Keyword(s):  
Friction And Wear ◽  
Silicon Oxide ◽  
Wear Behavior ◽  
Hexagonal Boron Nitride ◽  
Transition Metal Dichalcogenides ◽  
Water Layer ◽  
Adsorbed Water ◽  
Ambient Air ◽  
Ultrananocrystalline Diamond ◽  
Defect Sites

The friction and wear behavior of materials are not intrinsic properties, but extrinsic properties; in other words, they can drastically vary depending on test and environmental conditions. In ambient air, humidity is one such extrinsic parameter. This paper reviews the effects of humidity on macro- and nano-scale friction and wear of various types of materials. The materials included in this review are graphite and graphene, diamond-like carbon (DLC) films, ultrananocrystalline diamond (UNCD), transition metal dichalcogenides (TMDs), hexagonal boron nitride (h-BN), boric acid, silicon, silicon oxide, silicates, advanced ceramics, and metals. Details of underlying mechanisms governing friction and wear behaviors vary depending on materials and humidity; nonetheless, a comparison of various material cases revealed an overarching trend. Tribochemical reactions between the tribo-materials and the adsorbed water molecules play significant roles; such reactions can occur at defect sites in the case of two-dimensionally layered materials and carbon-based materials, or even on low energy surfaces in the case of metals and oxide materials. It is extremely important to consider the effects of adsorbed water layer thickness and structure for a full understanding of tribological properties of materials in ambient air.

Restricted Rotational Motion of InterlayerWaterMolecules in Vanadium Pentoxide Hydrate, V2O5·n D2O, as Studied by Deuterium NMR

2002 ◽  
Vol 57 (6-7) ◽  
pp. 419-424 ◽  
Author(s):  
Sadamu Takeda ◽  
Yuko Gotoh ◽  
Goro Maruta ◽  
Shuichi Takahara ◽  
Shigeharu Kittaka
Keyword(s):  
Double Layer ◽  
Vanadium Pentoxide ◽  
Rotational Motion ◽  
Interlayer Space ◽  
Layer Structure ◽  
Bond Distance ◽  
Adsorbed Water ◽  
Deuterium Nmr ◽  
Water Molecules ◽  
Layer Structures

The rotational behavior of the interlayer water molecules of deuterated vanadium pentoxide hydrate, V2O5.nD2O, was studied by solid-state deuterium NMR for the mono- and double-layer structures of the adsorbed water molecules. The rotational motion was anisotropic even at 355 K for both the mono- and double-layer structures. The 180° flipping motion about the C2-symmetry axis of the water molecule and the rotation around the figure axis, which makes an angle Ɵ with the C2-axis, occurred with the activation energy of (34±4) and (49±6) kJmol-1, respectively. The activation energies were almost independent of the mono- and double-layer structures of the water molecules, but the angle Ɵ made by the two axes varied from 33° for the monolayer to 25° for the double-layer at 230 K. The angle started to decrease above 250 K (e. g. the angle was 17 at 355 K for the double-layer structure). The results indicate that the average orientation of the water molecules in the two dimensional interlayer space depends on the layer structure and on the temperature. From the deuterium NMR spectrum at 130 K, the quadrupole coupling constant e2Qq/h = 240 kHz and the asymmetry parameter η= 0.12 were deduced. These values indicate the average hydrogen bond distance R(O H) = 2.0 Å for the D2O molecules in the 2D-interlayer space

Room Temperature Band-Edge Luminescence from Silicon Grains Prepared by the Recrystallization of Mesoporous Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
Karen L. Moore ◽  
Leonid Tsybeskov ◽  
Philippe M. Fauchet ◽  
Dennis G. Hall
Keyword(s):  
Room Temperature ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Band Edge ◽  
Applied Bias ◽  
Mesoporous Silicon ◽  
Room Temperature Photoluminescence ◽  
Band Edge Luminescence ◽  
A Current ◽  
Better Than

AbstractRoom-temperature photoluminescence (PL) peaking at 1.1 eV has been found in electrochemically etched mesoporous silicon annealed at 950°C. Low-temperature PL spectra clearly show a fine structure related to phonon-assisted transitions in pure crystalline silicon (c-Si) and the absence of defect-related (e.g.P-line) and impurity-related (e.g.oxygen, boron) transitions. The maximum PL external quantum efficiency (EQE) is found to be better than 0.1% with a weak temperature dependence in the region from 12K to 400K. The PL intensity is a linear function of excitation intensity up to 100 W/cm2. The PL can be suppressed by an external electric field ≥ 105 V/cm. Room temperature electroluminescence (EL) related to the c-Si band-edge is also demonstrated under an applied bias ≤ 1.2 V and with a current density ≈ 20 mA/cm2. A model is proposed in which the radiative recombination originates from recrystallized Si grains within a non-stoichiometric Si-rich silicon oxide (SRSO) matrix.

Long Luminescence Lifetime of 1.54 μ m Er3+ Luminescence from Erbium Doped Silicon Rich Silicon Oxide and its Origin

1998 ◽  
Vol 536 ◽  
Author(s):  
Se-Young Seo ◽  
Jung H. Shin ◽  
Choochon Lee
Keyword(s):  
Room Temperature ◽  
Radiative Decay ◽  
Silicon Oxide ◽  
Silicon Nanoclusters ◽  
Excitation Rate ◽  
Carrier Recombination ◽  
Erbium Doped ◽  
Doped Silicon ◽  
Almost All ◽  
Er Doped

AbstractThe photoluminescent properties of erbium doped silicon rich silicon oxide (SRSO) is investigated. The silicon content of SRSO was varied from 43 to 33 at. % and Er concentration was 0.4–0.7 at. % in all cases. We observe strong 1.54 μ m luminescence due to 4I13/2⇒4I15/2 Er3+ 4f transition, excited via energy transfer from carrier recombination in silicon nanoclusters to Er 4f shells. The luminescent lifetimes at the room temperature are found to be 4–7 msec, which is longer than that reported from Er in any semiconducting host material, and comparable to that of Er doped SiO2 and A12O3. The dependence of the Er3+ luminescent intensities and lifetimes on temperature, pump power and on background illumination shows that by using SRSO, almost all non-radiative decay paths of excited Er3+ can be effectively suppressed, and that such suppression is more important than increasing excitation rate of Er3+. A planar waveguide using Er doped SRSO is also demonstrated.

Investigation of silicon oxide films prepared by room-temperature ion plating

1998 ◽  
Vol 83 (2) ◽  
pp. 1107-1113 ◽  
Author(s):  
Ching-Fa Yeh ◽  
Tai-Ju Chen ◽  
Ching-Lin Fan ◽  
Jiann-Shiun Kao
Keyword(s):  
Room Temperature ◽  
Silicon Oxide ◽  
Oxide Films ◽  
Ion Plating

Light Emission from Intrinsic and Doped Silicon-Rich Silicon Oxide: from the Visible to 1.6 ΜM

1996 ◽  
Vol 452 ◽  
Author(s):  
L. Tsybeskov ◽  
K. L. Moore ◽  
P. M. Fauchet ◽  
D. G. Hall
Keyword(s):  
Rare Earth ◽  
External Quantum Efficiency ◽  
Room Temperature ◽  
Structural Modification ◽  
Silicon Oxide ◽  
Light Emission ◽  
Crystalline Silicon ◽  
Light Emitting ◽  
Infra Red ◽  
Doped Silicon

AbstractSilicon-rich silicon oxide (SRSO) films were prepared by thermal oxidation (700°C-950°C) of electrochemically etched crystalline silicon (c-Si). The annealing-oxidation conditions are responsible for the chemical and structural modification of SRSO as well as for the intrinsic light-emission in the visible and near infra-red spectral regions (2.0–1.8 eV, 1.6 eV and 1.1 eV). The extrinsic photoluminescence (PL) is produced by doping (via electroplating or ion implantation) with rare-earth (R-E) ions (Nd at 1.06 μm, Er at 1.5 μm) and chalcogens (S at ∼1.6 μm). The impurities can be localized within the Si grains (S), in the SiO matrix (Nd, Er) or at the Si-SiO interface (Er). The Er-related PL in SRSO was studied in detail: the maximum PL external quantum efficiency (EQE) of 0.01–0.1% was found in samples annealed at 900°C in diluted oxygen (∼ 10% in N2). The integrated PL temperature dependence is weak from 12K to 300K. Light emitting diodes (LEDs) with an active layer made of an intrinsic and doped SRSO are manufactured and studied: room temperature electroluminescence (EL) from the visible to 1.6 μmhas been demonstrated.

Effective performance improvement of organic thin film transistors by using tri-layer insulators

2018 ◽  
Vol 83 (2) ◽  
pp. 20201 ◽  
Author(s):  
Yao Ni ◽  
Jianlin Zhou ◽  
Yuanyuan Hao ◽  
Hang Yu ◽  
Yanyun Li ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Silicon Oxide ◽  
Layer Structure ◽  
Organic Thin Film Transistors ◽  
Organic Thin Film ◽  
Interface Quality ◽  
Organic Semiconductor Materials ◽  
Effective Performance ◽  
P Type

Organic thin film transistors (OTFTs) with silicon oxide (SiO2)/poly(4-vinylphenol) (PVP)/polymethylmethacrylate (PMMA) tri-layer structure (SPP) as dielectric layers have been fabricated. To verify the validity of such tri-layer structure, two different organic semiconductor materials such as p-type pentacene and n-type fluorinated copper phthalo–cyanine (F16CuPc) are both used for fabricating OTFTs. Comparing with the OTFTs even by using PMMA modification, the better interface quality existing between SPP dielectric and organic film leads a higher conductive efficiency for transport carriers in channel. And then the field effect carriers (hole in pentacene OTFTs and electron in F16CuPc OTFTs) mobilities are both increased obviously. Our results show the SPP dielectric structure can be widely used to improve performance of OTFTs.

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