Journal articles: 'Doping by nitrogen'

1

Ngidi, Nonjabulo P. D., Moses A. Ollengo, and Vincent O. Nyamori. "Effect of Doping Temperatures and Nitrogen Precursors on the Physicochemical, Optical, and Electrical Conductivity Properties of Nitrogen-Doped Reduced Graphene Oxide." Materials 12, no. 20 (October 16, 2019): 3376. http://dx.doi.org/10.3390/ma12203376.

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The greatest challenge in graphene-based material synthesis is achieving large surface area of high conductivity. Thus, tuning physico-electrochemical properties of these materials is of paramount importance. An even greater problem is to obtain a desired dopant configuration which allows control over device sensitivity and enhanced reproducibility. In this work, substitutional doping of graphene oxide (GO) with nitrogen atoms to induce lattice–structural modification of GO resulted in nitrogen-doped reduced graphene oxide (N-rGO). The effect of doping temperatures and various nitrogen precursors on the physicochemical, optical, and conductivity properties of N-rGO is hereby reported. This was achieved by thermal treating GO with different nitrogen precursors at various doping temperatures. The lowest doping temperature (600 °C) resulted in less thermally stable N-rGO, yet with higher porosity, while the highest doping temperature (800 °C) produced the opposite results. The choice of nitrogen precursors had a significant impact on the atomic percentage of nitrogen in N-rGO. Nitrogen-rich precursor, 4-nitro-ο-phenylenediamine, provided N-rGO with favorable physicochemical properties (larger surface area of 154.02 m2 g−1) with an enhanced electrical conductivity (0.133 S cm−1) property, making it more useful in energy storage devices. Thus, by adjusting the doping temperatures and nitrogen precursors, one can tailor various properties of N-rGO.

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Jorge, A. Belén, Jordi Fraxedas, Andrés Cantarero, Anthony J. Williams, Jennifer Rodgers, J. Paul Attfield, and Amparo Fuertes. "Nitrogen Doping of Ceria." Chemistry of Materials 20, no. 5 (March 2008): 1682–84. http://dx.doi.org/10.1021/cm7028678.

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Pöykkö, S., M. J. Puska, T. Korhonen, and R. M. Nieminen. "Nitrogen doping in ZnSe." Materials Science and Engineering: B 43, no. 1-3 (January 1997): 1–4. http://dx.doi.org/10.1016/s0921-5107(96)01823-5.

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Granzier-Nakajima, Tomotaroh, Kazunori Fujisawa, Vivek Anil, Mauricio Terrones, and Yin-Ting Yeh. "Controlling Nitrogen Doping in Graphene with Atomic Precision: Synthesis and Characterization." Nanomaterials 9, no. 3 (March 12, 2019): 425. http://dx.doi.org/10.3390/nano9030425.

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Graphene provides a unique platform for the detailed study of its dopants at the atomic level. Previously, doped materials including Si, and 0D-1D carbon nanomaterials presented difficulties in the characterization of their dopants due to gradients in their dopant concentration and agglomeration of the material itself. Graphene’s two-dimensional nature allows for the detailed characterization of these dopants via spectroscopic and atomic resolution imaging techniques. Nitrogen doping of graphene has been well studied, providing insights into the dopant bonding structure, dopant-dopant interaction, and spatial segregation within a single crystal. Different configurations of nitrogen within the carbon lattice have different electronic and chemical properties, and by controlling these dopants it is possible to either n- or p-type dope graphene, grant half-metallicity, and alter nitrogen doped graphene’s (NG) catalytic and sensing properties. Thus, an understanding and the ability to control different types of nitrogen doping configurations allows for the fine tuning of NG’s properties. Here we review the synthesis, characterization, and properties of nitrogen dopants in NG beyond atomic dopant concentration.

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Wang, Zhi Yong. "The Effects of Heteroatom-Doping in Stone-Wales Defects on the Electronic Properties of Graphene Nanoribbons." Advanced Materials Research 463-464 (February 2012): 793–97. http://dx.doi.org/10.4028/www.scientific.net/amr.463-464.793.

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The effects of boron(nitrogen/silicon)-dopant in Stone-Wales defects on electronic properties of graphene nanoribbons are investigated by using density functional theory. It is shown that the geometry structures and band structures have changed distinctly for these complex configurations. Interestingly for the dopant site 1, the distortions of boron/silicon-doping configurations are larger than that of the nitrogen-doping configurations, which affects the band structures of these configurations. The theoretical results may be valuable for the design of electronic devices.

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Namiki, Ryota, Takuya Suyama, Chihiro Izawa, Tomoko Ikeda-Fukazawa, Michiyo Honda, Tomoaki Watanabe, and Mamoru Aizawa. "Chemical State of Nitrogen in Nitrogen-Doped Hydroxyapatite Ceramics with Enhanced Bioactivity." Key Engineering Materials 720 (November 2016): 215–18. http://dx.doi.org/10.4028/www.scientific.net/kem.720.215.

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The chemical state of nitrogen which was induced into crystal structure of hydroxyapatite by nitrogen-doping method (N-doping method) was examined. Determination of lattice constants by powder X-ray diffraction (XRD) showed that the nitrogen species induced by N-doping method substituted the OH- ion in the crystal structure of hydroxyapatite. In addition, Fourier transform infrared spectroscopy (FT-IR) and temperature programmed desorption-mass spectroscopy (TPD-MS) determined that the chemical state of nitrogen induced by N-doping method was N2O.

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Sato, Go, Takahiro Numai, Mitsuo Hoshiyama, Ikuo Suemune, Hideaki Machida, and Norio Shimoyama. "Metalorganic MBE Growth of Nitrogen-doped ZnSe: TAN Doping and Nitrogen Plasma Doping." Japanese Journal of Applied Physics 35, Part 1, No. 2B (February 28, 1996): 1436–39. http://dx.doi.org/10.1143/jjap.35.1436.

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Ewels, C. P., and M. Glerup. "Nitrogen Doping in Carbon Nanotubes." Journal of Nanoscience and Nanotechnology 5, no. 9 (September 1, 2005): 1345–63. http://dx.doi.org/10.1166/jnn.2005.304.

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9

Burda, Clemens, Yongbing Lou, Xiaobo Chen, Anna C. S. Samia, John Stout, and James L. Gole. "Enhanced Nitrogen Doping in TiO2Nanoparticles." Nano Letters 3, no. 8 (August 2003): 1049–51. http://dx.doi.org/10.1021/nl034332o.

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10

Sun, Xi Lian, and Hong Tao Cao. "Effects of Nitrogen Doping on Optical Properties of Tungsten Oxide Thin Films." Advanced Materials Research 616-618 (December 2012): 1773–77. http://dx.doi.org/10.4028/www.scientific.net/amr.616-618.1773.

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In depositing nitrogen doped tungsten oxide thin films by using reactive dc pulsed magnetron sputtering process, nitrous oxide gas (N2O) was employed instead of nitrogen (N2) as the nitrogen dopant source. The nitrogen doping effect on the structural and optical properties of WO3 thin films was investigated by X-ray diffraction, transmission electron microscopy and UV-Vis spectroscopy. The thickness, refractive index and optical band gap energy of these films have been determined by analyzing the SE spectra using parameterized dispersion model. Morphological images reveal that the films are characterized by a hybrid structure comprising nanoparticles embeded in amorphous matrix and open channels between the agglomerated nanoparticles. Increasing nitrogen doping concentration is found to decrease the optical band gap energy and the refractive index. The reduced band gaps are associated with the N 2p orbital in the N-doped tungsten oxide films.

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11

Ou, Yi Yu, Valdas Jokubavicius, Chuan Liu, Rolf W. Berg, Margareta K. Linnarsson, Satoshi Kamiyama, Zhao Yue Lu, Rositza Yakimova, Mikael Syväjärvi, and Hai Yan Ou. "Photoluminescence and Raman Spectroscopy Characterization of Boron- and Nitrogen-Doped 6H Silicon Carbide." Materials Science Forum 717-720 (May 2012): 233–36. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.233.

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Nitrogen-boron doped 6H-SiC epilayers grown on low off-axis 6H-SiC substrates have been characterized by photoluminescence and Raman spectroscopy. The photoluminescence results show that a doping larger than 1018 cm-3 is favorable to observe the luminescence and addition of nitrogen is resulting in an increased luminescence. A dopant concentration difference larger than 4x1018 cm-3 is proposed to achieve intense photoluminescence. Raman spectroscopy further confirmed the doping type and concentrations for the samples. The results indicate that N-B doped SiC is being a good wavelength converter in white LEDs applications.

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12

Ikeda, Akihiro, Daichi Marui, Hiroshi Ikenoue, and Tanemasa Asano. "Extremely Enhanced Diffusion of Nitrogen in 4H-SiC Observed in Liquid-Nitrogen Immersion Irradiation of Excimer Laser." Materials Science Forum 821-823 (June 2015): 448–51. http://dx.doi.org/10.4028/www.scientific.net/msf.821-823.448.

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We report nitrogen (N) doping of 4H-SiC by KrF excimer laser irradiation in liquid N2. In comparison to phosphorus (P) doping performed using phosphoric acid solution, the liquid-N2 immersion-laser doping can introduce N atoms deeper (~ 1 μm depth) into the 4H-SiC, which results in reduction of doped layer resistance by approximately 3 orders of magnitude. Doping is shown to proceed by the thermal diffusion of species, while loss of the host material from the surface by ablation takes place at the same time. Chemical analysis shows that high density carbon (C) vacancies are generated in the N doped region, which suggests enhanced diffusion of N assisted by the presence of C vacancies. pn junction diodes are formed by using the N doping technique. Turn-on voltage is ~ -3V, which is reasonable for a pn junction diode of 4H-SiC.

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13

Park, Se Keun, Jun Ho Eun, and Hyun Ho Shin. "Nitrogen Doping to Metatitanic Acid by NH₃ Heat Treatment for Achieving Visible-Light-Responsive Photocatalytic Activity." Materials Science Forum 761 (July 2013): 35–39. http://dx.doi.org/10.4028/www.scientific.net/msf.761.35.

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Nitrogen doping can be achieved by heating TiO2-based photocatalyst powders under dopant-generating atmospheres such as NH3. In the present work, metatitanic acid (MTA) powder was used as a raw material to obtain nitrogen-doped titania using heat treatment in NH3flow. MTA is an industrially available intermediate product in sulfate process for TiO2production, which is mesoporous material with high specific surface area. The MTA powder was heat-treated in flowing NH3at 400–550°C. For comparison, commercial P25 TiO2powder was heat-treated under the same conditions. The results show that nitrogen dopant can be successfully incorporated into the MTA by heating in NH3 atmosphere. This obviously results in the enhanced visible-light photocatalytic activity, especially in MTA sample heated at 400°C. Due to the fascinating properties of MTA powder such as high specific surface area, the N-doping effect on MTA powder is much higher than the P25 TiO2powder.

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14

Yang, Deng-Tao, Tomoya Nakamura, Zhechang He, Xiang Wang, Atsushi Wakamiya, Tai Peng, and Suning Wang. "Doping Polycyclic Arenes with Nitrogen–Boron–Nitrogen (NBN) Units." Organic Letters 20, no. 21 (October 15, 2018): 6741–45. http://dx.doi.org/10.1021/acs.orglett.8b02850.

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15

Michalsky, Ronald, Peter H. Pfromm, and Aldo Steinfeld. "Rational design of metal nitride redox materials for solar-driven ammonia synthesis." Interface Focus 5, no. 3 (June 6, 2015): 20140084. http://dx.doi.org/10.1098/rsfs.2014.0084.

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Fixed nitrogen is an essential chemical building block for plant and animal protein, which makes ammonia (NH 3 ) a central component of synthetic fertilizer for the global production of food and biofuels. A global project on artificial photosynthesis may foster the development of production technologies for renewable NH 3 fertilizer, hydrogen carrier and combustion fuel. This article presents an alternative path for the production of NH 3 from nitrogen, water and solar energy. The process is based on a thermochemical redox cycle driven by concentrated solar process heat at 700–1200°C that yields NH 3 via the oxidation of a metal nitride with water. The metal nitride is recycled via solar-driven reduction of the oxidized redox material with nitrogen at atmospheric pressure. We employ electronic structure theory for the rational high-throughput design of novel metal nitride redox materials and to show how transition-metal doping controls the formation and consumption of nitrogen vacancies in metal nitrides. We confirm experimentally that iron doping of manganese nitride increases the concentration of nitrogen vacancies compared with no doping. The experiments are rationalized through the average energy of the dopant d-states, a descriptor for the theory-based design of advanced metal nitride redox materials to produce sustainable solar thermochemical ammonia.

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16

Oliveira, A. R., and M. N. P. Carreño. "In-Situ and Ion Implantation Nitrogen Doping on Near Stoichiometric a-SiC:H Films." Journal of Integrated Circuits and Systems 1, no. 2 (November 17, 2004): 26–30. http://dx.doi.org/10.29292/jics.v1i2.260.

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In this work we study the nitrogen n-type electrical doping of a-Si0.5C0.5:H films obtained by plasma enhanced chemical vapor deposition (PECVD) utilizing and comparing two doping techniques: in-situ (during the material growth) and ion implantation. The in-situ doped a-SiC:H films were obtained adding different amounts of N2 to the precursor gas mixture. For ion implantation four different nitrogen implanted concentrations were studied (between 1018 and 1021 atoms/ cm3) using multiple energies and doses to define a homogeneously doped layer. The doping experiments are carried out on a-SiC:H samples that present different structural order. The results show that high levels of electrical conductivity can be obtained with ion implantation technique. For in-situ technique the doping effect is also observed but must be improved in order to attain higher electrical conductivities. In the best case the room temperature dark conductivity for the sample implanted with 1021 nitrogens/cm3 was ~10-7 (Ω.cm)-1 and the activation energy was 0.2 eV. For in-situ doping the electrical dark conductivity reached values near 10-10 (Ω.cm)-1 at high temperatures and the activation energy was ~0.6 eV. Despite of the apparent low values of the electrical conductivity, these results are promising because we are dealing with a wide gap material and the doping processes are still not optimized.

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17

Gao, Xiang, Peng Wan Chen, Jian Jun Liu, Hao Yin, and Feng Lei Huang. "Effects of Shock Doping on the Energy Gap of TiO₂." Materials Science Forum 673 (January 2011): 149–54. http://dx.doi.org/10.4028/www.scientific.net/msf.673.149.

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In this paper, nitrogen-doped titania was achieved by detonation-driven flyer impacting on the mixtures of TiO2 and different nitrogen precursors. XRD、UV-Vis and XPS spectra were employed to characterize the phase composition, N doping concentration and energy gap of recovered samples. N doping concentration can be effectively regulated by choosing different doping nitrogen resources, changing initial content of doping nitrogen resources and flyer velocity in order to regulate the energy gap of TiO2. The maximum concentration of nitrogen of doped TiO2 by shock loading at 3.37 km/s is 13.45 at%. The results show that anatase transforms to rutile and srilankite appears at a higher flyer velocity (1.9-2.52km/s), the concentration of doped nitrogen in the recovered samples increases with increasing flyer velocity, the maximum concentration of nitrogen is 13.45 at%. The edge adsorption wavelength of nitrogen-doped titania induced by shock wave is shifted from 435nm to 730 nm and the corresponding energy gap is reduced from 2.85 eV to 1.73 eV.

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18

Furukawa, Ryoko, Yuno Yamamoto, Yoji Nabei, and Shunji Bandow. "Doping of boron or nitrogen to multilayered graphene grown on copper by thermal chemical vapor deposition of methane and vapor of phenylboronic acid or melamine." MRS Advances 4, no. 3-4 (2019): 211–16. http://dx.doi.org/10.1557/adv.2019.26.

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AbstractEither boron or nitrogen doped multilayered graphene was prepared by thermal chemical vapor deposition (CVD). Obtained heteroatom doped graphene was examined by Raman scattering, x-ray photo electron spectroscopy (XPS) and temperature dependence of sheet resistance. From the Raman scattering, obvious increase of ID/IG ratio could not be detected by boron doping, while it increased by ∼0.2 or more for nitrogen doped sample. From XPS, doping rates of boron and nitrogen were estimated to be in the range of 5∼12 at% and 1∼2 at%, respectively. XPS also showed that the boron and nitrogen atoms would locate at the doping sites of both graphitic and neighborhood of atomic defect. Magnitude of sheet resistance was decreased by either doping of boron or nitrogen.

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19

Cong, Ye, Peng Qin, Xuan Ke Li, Zhi Jun Dong, and Guan Ming Yuan. "Nitrogen and Lanthanum Co-Doped TiO₂ with Enhanced Photocatalytic Activity." Advanced Materials Research 179-180 (January 2011): 192–96. http://dx.doi.org/10.4028/www.scientific.net/amr.179-180.192.

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Nitrogen and lanthanum co-doped nanocsystalline titania photocatalysts were prepared by a homogeneous precipitation-hydrothermal process. The photocatalytic activity of the prepared samples on photodegradation of rhodamine B in visible light irradiation was studied. The nitrogen and lanthanum co-doping could greatly improve the photocatalytic activity of titania in visible light irradiation, probablely due to a synergistic effect of co-doping. The nitrogen doping could narrow the band gap of titania and enhance the utilization efficiency of visible light, while the lanthanum doping could accelerate the separation of photo-generated electrons and holes. Furthermore, the lanthanum doping could increase the adsorption of organic pollutants on the surface of photocatalyst.

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20

Sitaram, A. R., S. P. Murarka, and T. T. Sheng. "Grain growth in boron doped LPCVD polysilicon films." Journal of Materials Research 5, no. 2 (February 1990): 360–64. http://dx.doi.org/10.1557/jmr.1990.0360.

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Dopant induced grain growth in LPCVD polysilicon films has been investigated using BBr3 as the diffusion source at 900 and 950 °C. TEM and sheet resistance measurements indicate rapid growth under such doping conditions. Results are compared with the grain growth observed during (a) PBr3 doping of similar films, and (b) during anneals in ambients containing 1% oxygen in nitrogen, similar to that used during BBr3 or PBr3 doping. The results clearly demonstrate the rapid grain growth induced by both types of dopants, although phosphorus is more effective in inducing this grain growth.

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21

Forsberg, U., Ö. Danielsson, A. Henry, M. K. Linnarsson, and E. Janzén. "Nitrogen doping of epitaxial silicon carbide." Journal of Crystal Growth 236, no. 1-3 (March 2002): 101–12. http://dx.doi.org/10.1016/s0022-0248(01)02198-4.

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22

Zan, Recep, and Ali Altuntepe. "Nitrogen doping of graphene by CVD." Journal of Molecular Structure 1199 (January 2020): 127026. http://dx.doi.org/10.1016/j.molstruc.2019.127026.

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23

Zhou, Jiang‐Huai, Kengou Yamaguchi, Yoshikazu Yamamoto, and Tatsuo Shimizu. "Nitrogen doping in hydrogenated amorphous silicon." Journal of Applied Physics 74, no. 8 (October 15, 1993): 5086–89. http://dx.doi.org/10.1063/1.354293.

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24

Kaukonen, M., R. M. Nieminen, S. Pöykkö, and Ari P. Seitsonen. "Nitrogen Doping of Amorphous Carbon Surfaces." Physical Review Letters 83, no. 25 (December 20, 1999): 5346–49. http://dx.doi.org/10.1103/physrevlett.83.5346.

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25

Pichot, Vincent, Odile Stephan, Marc Comet, Eric Fousson, Julien Mory, Katia March, and Denis Spitzer. "High Nitrogen Doping of Detonation Nanodiamonds." Journal of Physical Chemistry C 114, no. 22 (May 13, 2010): 10082–87. http://dx.doi.org/10.1021/jp9121485.

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26

Singh, Jagriti, and R. C. Budhani. "Nitrogen doping in hydrogenated amorphous silicon." Solid State Communications 64, no. 3 (October 1987): 349–52. http://dx.doi.org/10.1016/0038-1098(87)90980-x.

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27

Van de Walle, Chris G., and D. B. Laks. "Nitrogen doping in ZnSe and ZnTe." Solid State Communications 93, no. 5 (February 1995): 447–50. http://dx.doi.org/10.1016/0038-1098(94)00815-9.

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28

Robertson, J., and C. A. Davis. "Nitrogen doping of tetrahedral amorphous carbon." Diamond and Related Materials 4, no. 4 (April 1995): 441–44. http://dx.doi.org/10.1016/0925-9635(94)05265-4.

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29

Stefanovich, V. A., S. V. Borisov, and A. V. Stefanovich. "The influence of nitrogen content on the amount of austenite in the structure of the deposited coatings obtained from diffusionsgleichung shavings of steel Р6M5." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 1 (April 10, 2019): 108–11. http://dx.doi.org/10.21122/1683-6065-2019-1-108-111.

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The article presents the results on the structure formation of deposited coatings obtained from steel chips P6M5 subjected to diffusion nitrogen-carbon doping. It was found that the diffusion doping with nitrogen-carbon steel chip waste P6M5 carbon content in them varies between 1.75–3.14%, nitrogen – 0.43–1.24%. The phase composition includes phases: a-Fe, M6C, Fe3C, (Cr, Fe)2N1–x, Fe3N, Cr0.63C0.35N0.03, M4(C, N) depending on the temperature and time of diffusion doping. When surfacing these materials in the deposited coating contains carbide-forming elements 8,6–9,3%, carbon 1,04–1,94%, nitrogen 0,08–0,25%. The structure consists of carbide M23S6, martensite and austenite, while the content of austenite in dendrites can reach 70–90%. It is shown that nitrogen doping of the deposited coatings obtained from steel chips P6M5, subjected to saturation with nitrogen-carbon, more effectively increases the amount of austenite in the structure than alloying the deposited coatings with nitrogen ferroalloys.

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30

Dragoman, Mircea, Silviu Vulpe, Elias Aperathithis, Chrysa Aivalioti, Cosmin Romanitan, Adrian Dinescu, Daniela Dragoman, et al. "Oxygen-vacancy induced ferroelectricity in nitrogen-doped nickel oxide." Journal of Applied Physics 131, no. 16 (April 28, 2022): 164304. http://dx.doi.org/10.1063/5.0075568.

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This paper reports the onset of ferroelectricity in NiO by breaking the crystallographic symmetry with oxygen vacancies created by N doping. Nitrogen-doped NiO was grown at room temperature by RF sputtering of Ni target in Ar–O2–N2 plasma on silicon and fused silica substrates. The impact of the nitrogen doping of NiO on microstructural, optical, and electrical properties has been investigated. According to x-ray diffraction investigations, by increasing the N doping level in NiO, a transition from (002) to a (111) preferential orientation for the cubic NiO phase was observed, as well as a lattice strain relaxation, that is usually ascribed to structural defect formation in crystal. The x-ray diffraction pole figures the presence of a distorted cubic structure in NiO and supports the Rietveld refinement findings related to the strain, which pointed out that nitrogen doping fosters lattice imperfections formation. These findings were found to be in agreement with our far-infrared measurements that revealed that upon nitrogen doping a structural distortion of the NiO cubic phase appears. X-ray photoemission spectroscopy measurements reveal the presence of oxygen vacancies in the NiO film following nitrogen doping. Evidence of ferroelectricity in nitrogen-doped NiO thin films has been provided by using the well-established Sawyer–Tower method. The results reported here provide the first insights on oxygen-vacancy induced ferroelectricity in nitrogen-doped nickel oxide thin films.

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MAO, YU-LIANG, XIAO-HONG YAN, YANG XIAO, JUE-XIAN CAO, and JUN XIANG. "FIRST-PRINCIPLES STUDY OF DOPED SINGLE WALL CARBON NANOTUBES." International Journal of Modern Physics C 16, no. 09 (September 2005): 1363–69. http://dx.doi.org/10.1142/s0129183105007984.

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We investigate boron and nitrogen substitutional doping single wall carbon nanotubes (SWCNTs) by first-principles calculations. The optimized geometres of boron and nitrogen substituted SWCNTs exhibit bamboo-like structures. Boron and nitrogen impurities form acceptor and donor states in semiconductor SWCNTs. The highest occupied molecular orbital (HOMO) indicates the trend of forming inter-tube bonds in doping SWCNTs. It may start a new way to form inter-tube bonds by doping in SWCNTs.

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32

Li, Shipu, Shiwei Lin, Jianjun Liao, Nengqian Pan, Danhong Li, and Jianbao Li. "Nitrogen-Doped TiO2Nanotube Arrays with Enhanced Photoelectrochemical Property." International Journal of Photoenergy 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/794207.

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N-doped TiO2nanotube arrays were prepared by electrochemical anodization in glycerol electrolyte, followed by electrochemical deposition in NH4Cl solution. An orthogonal experiment was used to optimize the doping conditions. Electrolyte concentration, reaction voltage, and reaction time were the main factors to influence the N-doping effect which was the determinant of the visible range photoresponse. The optimal N-doping conditions were determined as follows: reaction voltage is 3 V, reaction time is 2 h, and electrolyte concentration is 0.5 M. The maximal photocurrent enhanced ratio was 30% under white-light irradiation. About 58% improvement of photocatalytic efficiency was achieved in the Rhodamine B degradation experiment by N doping. The kinetic constant of the N-doped TNT arrays sample was almost twice higher than that of the undoped sample. Further analysis by X-ray photoelectron spectroscopy supported that electrochemical deposition is a simple and efficient method for N doping into TiO2nanotube arrays.

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33

Song, Jie, Rui Huang, Yi Zhang, Zewen Lin, Wenxing Zhang, Hongliang Li, Chao Song, Yanqing Guo, and Zhenxu Lin. "Effect of Nitrogen Doping on the Photoluminescence of Amorphous Silicon Oxycarbide Films." Micromachines 10, no. 10 (September 27, 2019): 649. http://dx.doi.org/10.3390/mi10100649.

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The effect of nitrogen doping on the photoluminescence (PL) of amorphous SiCxOy films was investigated. An increase in the content of nitrogen in the films from 1.07% to 25.6% resulted in red, orange-yellow, white, and blue switching PL. Luminescence decay measurements showed an ultrafast decay dynamic with a lifetime of ~1 ns for all the nitrogen-doped SiCxOy films. Nitrogen doping could also widen the bandgap of SiCxOy films. The microstructure and the elemental compositions of the films were studied by obtaining their Raman spectra and their X-ray photoelectron spectroscopy, respectively. The PL characteristics combined with an analysis of the chemical bonds configurations present in the films suggested that the switching PL was attributed to the change in defect luminescent centers resulting from the chemical bond reconstruction as a function of nitrogen doping. Nitrogen doping provides an alternative route for designing and fabricating tunable and efficient SiCxOy-based luminescent films for the development of Si-based optoelectronic devices.

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34

Wassner, Maximilian, Markus Eckardt, Andreas Reyer, Thomas Diemant, Michael S. Elsaesser, R. Jürgen Behm, and Nicola Hüsing. "Synthesis of amorphous and graphitized porous nitrogen-doped carbon spheres as oxygen reduction reaction catalysts." Beilstein Journal of Nanotechnology 11 (January 2, 2020): 1–15. http://dx.doi.org/10.3762/bjnano.11.1.

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Amorphous and graphitized nitrogen-doped (N-doped) carbon spheres are investigated as structurally well-defined model systems to gain a deeper understanding of the relationship between synthesis, structure, and their activity in the oxygen reduction reaction (ORR). N-doped carbon spheres were synthesized by hydrothermal treatment of a glucose solution yielding carbon spheres with sizes of 330 ± 50 nm, followed by nitrogen doping via heat treatment in ammonia atmosphere. The influence of a) varying the nitrogen doping temperature (550–1000 °C) and b) of a catalytic graphitization prior to nitrogen doping on the carbon sphere morphology, structure, elemental composition, N bonding configuration as well as porosity is investigated in detail. For the N-doped carbon spheres, the maximum nitrogen content was found at a doping temperature of 700 °C, with a decrease of the N content for higher temperatures. The overall nitrogen content of the graphitized N-doped carbon spheres is lower than that of the amorphous carbon spheres, however, also the microporosity decreases strongly with graphitization. Comparison with the electrocatalytic behavior in the ORR shows that in addition to the N-doping, the microporosity of the materials is critical for an efficient ORR.

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35

Steiner, Johannes, and Peter J. Wellmann. "Impact of Mechanical Stress and Nitrogen Doping on the Defect Distribution in the Initial Stage of the 4H-SiC PVT Growth Process." Materials 15, no. 5 (March 3, 2022): 1897. http://dx.doi.org/10.3390/ma15051897.

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Nitrogen incorporation changes the lattice spacing of SiC and can therefore lead to stress during physical vapor transport (PVT). The impact of the nitrogen-doping concentration during the initial phase of PVT growth of 4H-SiC was investigated using molten potassium hydroxide (KOH) etching, and the doping concentration and stress was detected by Raman spectroscopy. The change in the coefficient of thermal expansion (CTE) caused by the variation of nitrogen doping was implemented into a numerical model to quantitatively determine the stress induced during and after the crystal growth. Furthermore, the influence of mechanical stress related to the seed-mounting method was studied. To achieve this, four 100 mm diameter 4H-SiC crystals were grown with different nitrogen-doping distributions and seed-mounting strategies. It was found that the altered CTE plays a major role in the types and density of defect present in the grown crystal. While the mounting method led to increased stress in the initial seeding phase, the overall stress induced by inhomogeneous nitrogen doping is orders of magnitude higher.

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Bazin, Anne Elisabeth, Thierry Chassagne, Jean François Michaud, André Leycuras, Marc Portail, Marcin Zielinski, Emmanuel Collard, and Daniel Alquier. "Low Specific Contact Resistance to 3C-SiC Grown on (100) Si Substrates." Materials Science Forum 556-557 (September 2007): 721–24. http://dx.doi.org/10.4028/www.scientific.net/msf.556-557.721.

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In this work, ohmic contacts, formed by 100nm Ni layer RTA annealed or not, were investigated on 3C-SiC epilayers exhibiting different nitrogen doping levels. The epilayers were grown on (100) silicon. Doping level (N) and eventual dopant contamination (Al) were analyzed by C-V and/or SIMS. The specific contact resistance was determined by using Transmission Line Model (TLM) patterns for each condition (doping and annealing). Our results clearly evidence that very low specific contact resistance (~10-51.cm²) is obtained on highly doped 3C-SiC epilayers, enlightening the interest of both material and Ni contacts for future devices fabrication.

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Liao, Yu Qiao, Hong Kuan Yuan, An Long Kuang, Bo Wu, Yu Feng, Zhong Lin Liu, and Hong Chen. "Ferromagnetism and Electronic Structure in Nitrogen-Doped ZnO Nanowire: First-Principle Calculation." Applied Mechanics and Materials 130-134 (October 2011): 1435–38. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.1435.

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The nitrogen dopants can convert the nonmagnetic ZnO into a ferromagnet based on first-principle calculations. The formation of oxygen substituted with nitrogen on the surface is much easier than that inside nanowire. Calculation results indicate per N dopant can produce a total moment of 1.00 uBin the nitrogen-doped ZnO, the magnetic moments mainly come from the unpaired 2porbit split of N atom. Our theoretical study not only demonstrates the ZnO nanowire can be magnetic even without transition-metal doping, but also suggests that introducing N dopant is an effective way to fabricate low-dimensional magnetic ZnO nanostrucres.

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Calabretta, Cristiano, Viviana Scuderi, Ruggero Anzalone, Marco Mauceri, Danilo Crippa, Annalisa Cannizzaro, Simona Boninelli, and Francesco La Via. "Effect of Nitrogen and Aluminum Doping on 3C-SiC Heteroepitaxial Layers Grown on 4° Off-Axis Si (100)." Materials 14, no. 16 (August 6, 2021): 4400. http://dx.doi.org/10.3390/ma14164400.

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This work provides a comprehensive investigation of nitrogen and aluminum doping and its consequences for the physical properties of 3C-SiC. Free-standing 3C-SiC heteroepitaxial layers, intentionally doped with nitrogen or aluminum, were grown on Si (100) substrate with different 4° off-axis in a horizontal hot-wall chemical vapor deposition (CVD) reactor. The Si substrate was melted inside the CVD chamber, followed by the growth process. Micro-Raman, photoluminescence (PL) and stacking fault evaluation through molten KOH etching were performed on different doped samples. Then, the role of the doping and of the cut angle on the quality, density and length distribution of the stacking faults was studied, in order to estimate the influence of N and Al incorporation on the morphological and optical properties of the material. In particular, for both types of doping, it was observed that as the dopant concentration increased, the average length of the stacking faults (SFs) increased and their density decreased.

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Zhu, Zheng, Wei Cao, Xiaoming Huang, Zheng Shi, Dong Zhou, and Weizong Xu. "Analysis of Nitrogen-Doping Effect on Sub-Gap Density of States in a-IGZO TFTs by TCAD Simulation." Micromachines 13, no. 4 (April 14, 2022): 617. http://dx.doi.org/10.3390/mi13040617.

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In this work, the impact of nitrogen doping (N-doping) on the distribution of sub-gap states in amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) is qualitatively analyzed by technology computer-aided design (TCAD) simulation. According to the experimental characteristics, the numerical simulation results reveal that the interface trap states, bulk tail states, and deep-level sub-gap defect states originating from oxygen-vacancy- (Vo) related defects can be suppressed by an appropriate amount of N dopant. Correspondingly, the electrical properties and reliability of the a-IGZO TFTs are dramatically enhanced. In contrast, it is observed that the interfacial and deep-level sub-gap defects are increased when the a-IGZO TFT is doped with excess nitrogen, which results in the degeneration of the device’s performance and reliability. Moreover, it is found that tail-distributed acceptor-like N-related defects have been induced by excess N-doping, which is supported by the additional subthreshold slope degradation in the a-IGZO TFT.

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Guruswamy, B., V. Ravindrachary, C. Shruthi, and M. Mylarappa. "Effect of SnO₂ Nanoparticle Doping on Structural, Morphological and Thermal Properties of PVA-PVP Polymer Blend." Materials Science Forum 962 (July 2019): 82–88. http://dx.doi.org/10.4028/www.scientific.net/msf.962.82.

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The n-type semiconductor SnO2 nanoparticles were synthesised using standard route and the effect of this nanoparticle doping on structural, morphological and thermal properties of PVA-PVP polymer blend has been investigated. Pure and PVA-PVP/SnO2 Nanocomposite films were prepared using solution casting technique. The powder X-ray diffraction result shows that the crystalline nature of the blend increases with doping level. FESEM study shows that the surface morphology of the polymer nanocomposite varies with doping level. AFM study reveals that in the nanocomposite films, the average roughness changes with dopant concentration. The DSC studies on the samples were performed from 40°C to 400°C under nitrogen atmosphere and it shows that the thermal properties of the blend changes with doping concentration.

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Garino, Nadia, Adriano Sacco, Angelica Chiodoni, Candido F. Pirri, and Micaela Castellino. "Microwave-Assisted Synthesis of Nitrogen and Sulphur Doped Graphene Decorated with Antimony Oxide: An Effective Catalyst for Oxygen Reduction Reaction." Materials 15, no. 1 (December 21, 2021): 10. http://dx.doi.org/10.3390/ma15010010.

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In this study, we report on the facile synthesis of a novel electrocatalysts for the oxygen reduction reaction (ORR), based on reduced graphene oxide (RGO), functionalized with metallic and non-metallic elements. In particular, thanks to a fast one-pot microwave-assisted procedure, we induced, in the RGO graphene lattice, a combined doping with nitrogen and sulphur, and the simultaneous decoration with antimony oxide nanocrystals. The multi-doped–decorated material shows enhanced catalytic performance towards ORR, with respect to common nitrogen- or sulphur-doped carbon-based materials. The presence of co-doping is confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy analysis. The detailed electrochemical characterization shows the simultaneous effects of dopant atoms on the catalytic behavior. In particular, the importance of nitrogen and sulphur atoms in driving the oxygen absorption, together with the role of antimony in enhancing the electrochemical performance toward the ORR, are discussed.

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Li, Xu, Jianguo Zhou, Jitong wang, Wenming Qiao, Licheng Ling, and Donghui Long. "Large-scale synthesis of mesoporous carbon microspheres with controllable structure and nitrogen doping using a spray drying method." RSC Adv. 4, no. 107 (2014): 62662–65. http://dx.doi.org/10.1039/c4ra11799a.

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A low-cost and high-throughput spray drying method was developed to produce mesoporous carbon microspheres with controllable structure and nitrogen doping. The obtained microspheres have spherical morphology, controllable nitrogen doping (0–7 wt%) and large mesopores.

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Senzaki, Junji, Atsushi Shimozato, Kenji Fukuda, and Kazuo Arai. "Reliability of Thermal Oxides Grown on n-Type 4H-SiC Implanted with Low Nitrogen Concentration." Materials Science Forum 600-603 (September 2008): 779–82. http://dx.doi.org/10.4028/www.scientific.net/msf.600-603.779.

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Reliability of thermal oxides grown on the n-type 4H-SiC substrates implanted by nitrogen ion with low doping levels equal to or less than 1x1018 cm-3 has been investigated. The surface morphology becomes rough by the nitrogen implantation and the post implantation annealing. The field-to-breakdown value decreases with increase in the nitrogen concentration. The average EBD values are 11.6 MV/cm, 11.3 MV/cm and 10.7 MV/cm for the samples without the implantation and with the nitrogen implantation of doping levels of 1x1017 cm-3 and 1x1018 cm-3, respectively. The time-to-breakdown values were also degraded with the increase of the nitrogen implantation doping level. The reliability degradation of thermal oxides is caused by the implantation-induced breakdown factor.

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Kuganathan, Navaratnarajah. "Chalcogen Atom-Doped Graphene and Its Performance in N2 Activation." Surfaces 5, no. 2 (April 1, 2022): 228–37. http://dx.doi.org/10.3390/surfaces5020016.

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In this work, we studied dispersion correction, adsorption and substitution of chalcogen dopants (O, S, Se and Te) on the surface of graphene using density functional theory. The results reveal that a single oxygen atom is more preferred for adsorption onto the graphene surface than the other dopants, with an adsorption energy of −0.84 eV. The preference of this dopant is evidenced by a greater charge transfer of 0.34 electrons from the graphene surface to the oxygen. The substitutional doping of oxygen is energetically more favourable than the doping of other atoms. While nitrogen activation is enhanced by the adsorption, the activation is not significant with the doping of chalcogen atoms.

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Chindanon, Krista, Huang De Lin, Galyna Melnychuk, and Yaroslav Koshka. "Nitrogen Doping in Low-Temperature Halo-Carbon Homoepitaxial Growth of SiC." Materials Science Forum 600-603 (September 2008): 159–62. http://dx.doi.org/10.4028/www.scientific.net/msf.600-603.159.

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In this work, nitrogen doping was investigated during the low-temperature halo-carbon epitaxial growth of 4H-SiC on Si- and C-faces. The dependencies of nitrogen incorporation on nitrogen flow rate, Si/C ratio, growth rate, and temperature were investigated. It was established that the efficiency of nitrogen incorporation for the C-face growth at 1300 °C is higher than that for the Si-face for a wide range of the growth conditions. Seeming deviation of the Si/C ratio dependence from the “site-competition” trend confirmed the critical role of the silicon vapor condensation during the low-temperature epitaxy. Opposite trends for the nitrogen doping dependence on the growth rate were observed on the Si- and C-faces. Finally, a complex temperature dependence of the nitrogen doping in the temperature range from 1300 to 1450 0C was observed.

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46

Siddharthan, R., P. Mahalingam, E. Kanagaraj, and K. Saravanan. "Microwave Assisted Chemical Modification of Graphite Oxide for Supercapacitor Application." Asian Journal of Chemistry 33, no. 11 (2021): 2621–25. http://dx.doi.org/10.14233/ajchem.2021.23346.

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In present work, graphite oxide was chemically modified with boron, nitrogen and sulfur co-doping in a simple, single step green method by microwave treatment. Borax, urea and thiourea were used as precursors for doping. Mixtures of graphite oxide with precursors were microwave treated using domestic microwave oven at 800 W for 5 min. The products obtained were characterized for its morphology, structure, composition and electrical properties. The results showed that simultaneous reduction of graphite oxide and doping of boron, nitrogen and sulfur were occurred. The elemental doping distorts the structure without much affecting the crystalline nature. The boron, nitrogen and sulfur elements were doped in graphite oxide to the extent of 9.97 at%, 2.67 at% and 0.84 at%, respectively. The cyclic voltammetry and electrochemical impedance spectroscopy studies showed that boron, nitrogen and sulfur co-doped graphite oxide could be a suitable material for supercapacitor application.

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47

Eto, Kazuma, Hiromasa Suo, Tomohisa Kato, and Hajime Okumura. "Growth of Low Resistivity p-Type 4H-SiC Crystals by Sublimation with Using Aluminum and Nitrogen Co-Doping." Materials Science Forum 858 (May 2016): 77–80. http://dx.doi.org/10.4028/www.scientific.net/msf.858.77.

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Low resistivity p-type SiC bulk crystals were grown by the sublimation method with using aluminum and nitrogen co-doping. In the sublimation growth of 4H-SiC, to obtain low-resistive p-type crystals are not easy because of the instability of 4H-SiC polytype with highly Al-doping. We have grown < 90 mΩcm p-type 4H-SiC bulk crystals with the co-doping condition. The results of SIMS and Raman spectroscopy show that high concentration of nitrogen co-doping could be effective to the stabilization of 4H polytype with p-type SiC growth.

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Muramatsu, Hiroyuki, Masahiro Takahashi, Cheon-Soo Kang, Jin Hee Kim, Yoong Ahm Kim, and Takuya Hayashi. "Synthesis of outer tube-selectively nitrogen-doped double-walled carbon nanotubes by nitrogen plasma treatment." Nanoscale 10, no. 34 (2018): 15938–42. http://dx.doi.org/10.1039/c8nr03745k.

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49

VanMil, Brenda L., Kok Keong Lew, Rachael L. Myers-Ward, Ronald T. Holm, D. Kurt Gaskill, and Charles R. Eddy. "In Situ Measurement of Nitrogen during Growth of 4H-SiC by CVD." Materials Science Forum 556-557 (September 2007): 125–28. http://dx.doi.org/10.4028/www.scientific.net/msf.556-557.125.

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Real-time analysis of downstream nitrogen process-gas flows during 4H-SiC growth is reported. A Hiden Analytical HPR-20 quadrupole mass-spectrometer (QMS) was used to measure the process gas composition in the gas-stream of a hot-wall chemical vapor deposition (CVD) reactor. Using the 28 amu peak, it was found that the nitrogen partial pressure measured by the mass spectrometer directly correlates to the expected partial pressure of nitrogen in the process cell based on input flows. Two staircase doping samples were grown to track doping variations. The nitrogen mass flow was varied and corresponded to doping levels ranging from 1x1015 cm-3 to 8x1018 cm-3. Electron and nitrogen concentrations in the epilayers were measured by capacitancevoltage (CV) profiling and secondary ion mass spectrometry (SIMS), respectively. These efforts show real-time QMS monitoring is effective during growth for determining relative changes in nitrogen concentration in the gas flow, and thus, the level of nitrogen incorporation into the growing layer.

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GARG, ISHA, KEYA DHARAMVIR, V. K. JINDAL, and HITESH SHARMA. "A FIRST-PRINCIPLE INVESTIGATION OF BORON- AND NITROGEN-DOPED HETEROFULLERENES." International Journal of Nanoscience 10, no. 01n02 (February 2011): 29–33. http://dx.doi.org/10.1142/s0219581x11007430.

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A systematic study of structural, electronic and vibrational properties of boron- and nitrogen-doped heterofullerenes has been performed. N and B doping lead to the structural deformation, and the dopant has a tendency to occupy a single position in a pentagon and two positions in a hexagon which are not adjacent. B -substitution produces clusters of greater thermodynamic stability than N substitution. The C–N and C–B bond lengths lie in the range of 1.40–1.44 Å and 1.53–1.57 Å for hexagon–hexagon (6, 6) and 1.39–1.46 Å and 1.55–1.60 Å at pentagon–hexagon (5, 6) interfaces, respectively. The Mulliken charge analysis shows a charge transfer of -0.30 to -0.45 electrons from N to C atoms; B atom act as electron acceptors with charge gain ranging between -0.59 to -0.70 electrons. N - and B -doping in fullerene molecules present an interesting way to alter electronic and chemical properties of the C 60 molecule for useful device applications.

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Journal articles on the topic 'Doping by nitrogen'

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