Characterization of Carbon Nitride Films Prepared by Magnetic Filtered Plasma Deposition

1997 ◽  
Vol 498 ◽  
Author(s):  
Aixiang Wei ◽  
Dihu Chen ◽  
N. Ke ◽  
Shaoqi Peng ◽  
S. P. Wong

ABSTRACTCarbon nitride films prepared by magnetic filtered plasma deposition were characterized using Fourier transform infrared (FTIR) absorption and X-ray photoelectron spectroscopy (XPS). Characteristic bands corresponding to C-N, C=N, C=N, and C=C bonds were observed in FTIR spectra. It was found that the XPS C 1s and N 1s signals could be deconvoluted into three and two gaussian peaks, respectively. A plausible suggestion on the assignments of the XPS peaks to C3N4, CNx and ta-C phases was discussed. The relative abundance of the various CN bonds, the relative abundance of the various bonding components from XPS results, and their dependence on the nitrogen partial pressure PN during deposition were analyzed. Assuming the assignments of the XPS peaks to the various phases, the XPS results suggested that there would be an optimal PN that would favor the growth of the C3N4 phase. The electrical conductivity, the optical band gap and the Vickers hardness of these films were measured and the effects of PN on these properties were studied.

1992 ◽  
Vol 270 ◽  
Author(s):  
Haojie Yuan ◽  
R. Stanley Williams

ABSTRACTThin films of pure germanium-carbon alloys (GexC1−x with x ≈ 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) have been grown on Si(100) and A12O3 (0001) substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray θ-2θ diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these new materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00eV to 0.85eV for x = 0.0 to 1.0 respectively. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples has a bonding configuration that is a mixture of sp2 and sp3 hybridizations.


2014 ◽  
Vol 787 ◽  
pp. 205-209
Author(s):  
Yue Chao Hu ◽  
Zhi Gang Zou ◽  
Ke Feng Cai

CuxBi2Te3films were prepared by chronopotentiometry electro-deposition on indium tin oxide (ITO)-coated glass substrates from an aqueous acidic electrolyte at room temperature. The films were deposited at the same current density but in electrolyte with different Cu2+concentrations: 0.1, 0.25, 0.5, 0.75 or 1mM. The phase composition and morphology of the films were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and field emission scanning electron microscope, respectively. The electrical conductivity and Seebeck coefficient of the CuxBi2Te3films were measured after being transferred onto a non-conductive rubberized fabric support. All the films showed n-type conduction with Seebeck coefficient in the range of-63 to-84μV/K, and the electrical conductivity in the range of 90 to 185S/cm. The film deposited from an electrolyte with 0.5mM Cu2+showed higher power factor ~130 μW/K-2m-1.


2002 ◽  
Vol 725 ◽  
Author(s):  
Salvador Borrós ◽  
M.Paz Diago ◽  
Joan Esteve ◽  
Núria Agulló

AbstractIn this work, thin films (thickness ∼ 0.5 μm) were obtained by plasma polymerization of pyrrole (Ppy) and thiophene (Pth) at 25-30 W and 0.1-0.2 mbar of pressure. Further doping with iodine was carried out to some of the Ppy and Pth films (Ppy/I2, Pth/I2) in order to enhance their electrical conductivity properties.Structural and morphological characterization of both Ppy and Pth as well as of Ppy/I2 and Pth/I2 was performed using Infrared Spectroscopy (IR), X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM).In the light of the information given by IR, XPS and AFM techniques, exhaustive and accurate description of both undoped and I2/doped Ppy and Pth films obtained by Plasma Polymerization is attained.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1518
Author(s):  
Minsu Kim ◽  
Dabin Park ◽  
Jooheon Kim

Herein, Sb2Se3 and β-Cu2Se nanowires are synthesized via hydrothermal reaction and water evaporation-induced self-assembly methods, respectively. The successful syntheses and morphologies of the Sb2Se3 and β-Cu2Se nanowires are confirmed via X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), and field emission transmission electron microscopy (FE-TEM). Sb2Se3 materials have low electrical conductivity which limits application to the thermoelectric generator. To improve the electrical conductivity of the Sb2Se3 and β-Cu2Se nanowires, polyaniline (PANI) is coated onto the surface and confirmed via Fourier-transform infrared spectroscopy (FT-IR), FE-TEM, and XPS analysis. After coating PANI, the electrical conductivities of Sb2Se3/β-Cu2Se/PANI composites were increased. The thermoelectric performance of the flexible Sb2Se3/β-Cu2Se/PANI films is then measured, and the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is shown to provide the highest power factor of 181.61 μW/m·K2 at 473 K. In addition, a thermoelectric generator consisting of five legs of the 70%-Sb2Se3/30%-β-Cu2Se/PANI film is constructed and shown to provide an open-circuit voltage of 7.9 mV and an output power of 80.1 nW at ΔT = 30 K. This study demonstrates that the combination of inorganic thermoelectric materials and flexible polymers can generate power in wearable or portable devices.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1646
Author(s):  
Junyi Li ◽  
Neeta Karjule ◽  
Jiani Qin ◽  
Ying Wang ◽  
Jesús Barrio ◽  
...  

Carbon nitride materials require high temperatures (>500 °C) for their preparation, which entails substantial energy consumption. Furthermore, the high reaction temperature limits the materials’ processability and the control over their elemental composition. Therefore, alternative synthetic pathways that operate under milder conditions are still very much sought after. In this work, we prepared semiconductive carbon nitride (CN) polymers at low temperatures (300 °C) by carrying out the thermal condensation of triaminopyrimidine and acetoguanamine under a N2 atmosphere. These molecules are isomers: they display the same chemical formula but a different spatial distribution of their elements. X-ray photoelectron spectroscopy (XPS) experiments and electrochemical and photophysical characterization confirm that the initial spatial organization strongly determines the chemical composition and electronic structure of the materials, which, thanks to the preservation of functional groups in their surface, display excellent processability in liquid media.


2014 ◽  
Vol 34 (3) ◽  
pp. 841-849 ◽  
Author(s):  
M. Kanuchova ◽  
L. Kozakova ◽  
M. Drabova ◽  
M. Sisol ◽  
A. Estokova ◽  
...  

2003 ◽  
Vol 18 (5) ◽  
pp. 1123-1130 ◽  
Author(s):  
V. Oliveira ◽  
R. Vilar

This paper aims to contribute to the understanding of column formation mechanisms in Al2O3–TiC ceramics micromachined using excimer lasers. Chemical and structural characterization of columns grown in Al2O3–TiC composite processed with 200 KrF laser pulses at 10 J/cm2 was carried out by scanning electron microscopy, transmission electron microscopy, x-ray photoelectron spectroscopy, and x-ray diffraction analysis. Fully developed columns consist of a core of unprocessed material surrounded by an outer layer of Al2TiO5, formed in oxidizing conditions, and an inner layer, formed in reducing conditions, composed of TiC and Al3Ti or an AlTi solid solution. Possible mechanisms of column formation are discussed.


2011 ◽  
Vol 415-417 ◽  
pp. 642-647
Author(s):  
En Zhong Li ◽  
Da Xiang Yang ◽  
Wei Ling Guo ◽  
Hai Dou Wang ◽  
Bin Shi Xu

Ultrafine fibers were electrospun from polyacrylonitrile (PAN)/N,N-dimethyl formamide (DMF) solution as a precursor of carbon nanofibers. The effects of solution concentration, applied voltage and flow rate on preparation and morphologies of electrospun PAN fibers were investigated. Morphologies of the green fibers, stabilized fibers and carbonized fibers were compared by scanning electron microscope (SEM). The diameter of PAN nanofibers is about 450nm and the distribution of diameter is well-proportioned. Characterization of the elements changes of fibers were performed by X-ray photoelectron spectroscopy (XPS).


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