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Właściwości elektryczne monokryształów krzemu wzbogaconych w azot

Kamiński P., Kwestarz M., Surma B.

Materiały Elektroniczne

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2015

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T. 43, nr 4

31--38

PL

W artykule omówiono właściwości elektryczne monokryształów krzemu domieszkowanych azotem. Opisano sposób wbudowywania się atomów azotu do sieci krystalicznej Si. Przedstawiono mechanizm wpływu atomów azotu na anihilację mikrodefektów typu voids związanych z agregatami luk. Dla wzbogaconego w azot monokryształu krzemu o wysokiej rezystywności otrzymanego metodą pionowego topienia strefowego (FZ – Floating Zone) pokazano radialny rozkład rezystywności oraz radialny rozkład koncentracji azotu. Stwierdzono możliwość wpływu kompleksów złożonych z atomów azotu i atomów tlenu (N - O) na właściwości elektryczne otrzymywanych metodą FZ monokryształów Si wzbogaconych w azot.

EN

This paper presents the electrical properties of silicon single crystals doped with nitrogen. The incorporation of nitrogen atoms into the Si lattice is described. The mechanism showing the effect of the nitrogen atoms on the annihilation of void type microdefects associated with vacancy aggregates is given. For a high resistivity, nitrogen-enriched silicon single crystal, obtained by the Floating Zone (FZ) method, the radial distributions of both resistivity and nitrogen concentration are shown. The possible effect of nitrogen-oxygen (N - O) complexes on the electrical properties of nitrogen-enriched FZ Si single crystals is discussed.

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The influence of nitrogen doping on self-ignition of hydrogen during high-pressure release into air – numerical investigation

Dziubanii K., Rudy W., Teodorczyk A.

Archivum Combustionis

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2013

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Vol. 33 nr 4

215--225

EN

Hydrogen is expected to be a future alternative fuel. However, its implementation as a widely used energy carrier is difficult because of its tendency for leakage and ignition during pressurized release into air - hydrogen must be stored in tanks under high pressure. Up to now, in the studies on hydrogen self-ignition the influence of the nitrogen addition was not taken into account. This phenomenon is numerically investigated in this paper. The computations were conducted using a commercial CFD code AVL Fire. Examined domain was formed of two tanks – one filled with fuel (H2-N2 mixture) and second filled with oxidizer (air) connected by a tube. The length of the tube ranged from 10 mm to 80 mm. Conducted numerical simulations show that for longer tubes the ignition occurs inside the tube and initial pressure necessary for ignition decreases as the tube length increases. It is also demonstrated that rising initial pressure decreases the ignition delay time.

3

Electron emission from nitrogen-doped polycrystalline diamond/Si heterostructures

Staryga E., Fabisiak K., Dłużniewski M., Bąk G.

Materials Science Poland

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2012

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Vol. 30, No. 4

390--397

EN

The field electron emission from polycrystalline diamond/silicon and nitrogen-doped polycrystalline diamond/silicon structures obtained by HF CVD deposition method has been investigated. Electron emission currents from the samples were measured in a chamber at the pressure equal to 2ź106 Pa in sphere-to-plane diode configuration with the 5 žm distance between electrodes. As expected, the results confirm the relation between the structure of diamond films and their emission properties. The type of silicon substrate also infiuences the value of emission currents and the diamond/n-Si heterostructures exhibit better electron emission than diamond/p-Si ones. The nitrogen doping significantly enhances the electron emission from the heterostructures and their emission parameters. The values of the threshold field between 2 V/žm and 3 V/žm were registered, the values of emission current close to 1 mA/cm2at 5 V/žm for the nitrogen-doped films were obtained. The shape of current-voltage characteristics for nitrogen-doped polycrystalline films may be interpreted in terms of stochastic distribution of diameters of conducting channels which form the emission centers.

4

Chemical characteristics of new nanopowder of titania doped with nitrogen atoms

Szybowska K., Gazda M., Lisowska-Oleksiak A.

Advances in Materials Science

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2009

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Vol. 9, nr 3(21)

23-38

EN

Characteristics of new nitrogen doped TiO2 prepared in an one-pot synthesis where titania (IV) complexes with ligands containing nitrogen atoms were used as a precursor are presented in this paper. The pale yellow nanopowder with crystallite size of 9 – 12 nm is obtained as a product of calcination at 310°C and repeated washing procedure. Elemental analysis shows that nitrogen (1.087 at. pct.) is present in obtained material. The morphology and microstructure of samples were examined by XRD, AFM, UV-VIS and FTIR-ATR techniques. These studies confirm that obtained powder demonstrates a significant decrease in the band gap energy value (Eg = 2.83 eV) comparing to pure TiO2 (Eg 3.22 eV). Presence of N-Ti-O bonds was confirmed via FTIR ATR. Products of the powder thermal decomposition were detected using TG-DSC technique coupled with mass spectrometry (MS). The report presents electrochemical studies which allow estimation of a flatband potential Efb on the basis of the Mott-Schottky relation.