Qualitative analysis of a diamondlike carbon film by angle-resolved x-ray photoelectron spectroscopy

Abstract

Angle-resolved x-ray photoelectron spectroscopy was used to investigate the surface of a diamondlike carbon film prepared by the ionized deposition method. We then analyzed the C 1s spectra using the Doniach-Šunjić (DŠ) [J. Phys. C 3, 285 (1970)] function convoluted with a Gaussian function. Consequently, we obtained four fitting curves for the carbon components in each spectrum, regardless of the assumption of the singularity index (α) in the DŠ function, which expresses the asymmetry of the C 1s spectrum. The curves were assigned in the order of binding energy to bulk sp3 carbon (283.7–283.8eV), bulk sp2 carbon (284.2–284.3eV), surface sp2 carbon (284.7–284.8eV), and surface sp3 (285.3–285.4eV) carbon. We further considered the influence of the assumption of α. Consequently, we suggest that the C 1s spectra can be quantitatively analyzed without considering the influences of α when the ratio of α for sp2 carbon to that for sp3 carbon [α(sp2):α(sp3)] is between 10:0 and 5:5. The distribution in the α ratio may indicate that the sp2 and the sp3 carbon atoms can interact with each other (hybridization) and differ from those highly oriented pyrolytic graphite and diamond, respectively.

X‐ray photoelectron analysis of surface functional groups on diamond‐like carbon films by gas‐phase chemical derivatization method

“…[13,15] The carbon source was 30 sccm of benzene gas, the DC bias voltage applied to the substrate was −2 kV, and the temperature was 180…”

Annealing effect on the chemical structure of diamondlike carbon

“…8,[23][24][25][26] The deposition conditions were as follows: the carbon source was 30 SCCM ͑SCCM denotes cubic centimeter per minute at STP͒ of benzene gas. 8,[23][24][25][26] The deposition conditions were as follows: the carbon source was 30 SCCM ͑SCCM denotes cubic centimeter per minute at STP͒ of benzene gas.…”

“…[3][4][5] X-ray photoelectron spectroscopy ͑XPS͒ provides important information on the surface chemical structures of materials as the shifts of the binding energy ͑E B ͒. 8 Hydrogen in DLC plays an important role: hydrogencarbon ͑H-C͒ bonds in DLC produce large free spaces in the structure, which inhibit conductive routes and lead to high electrical resistivity. Clues to decompose the spectrum can be obtained by systematically comparing the spectral features taken under different conditions.…”

Electrons: Entrapment and Polarization

“…CdS-S 2p [29] 163.9 162.7 161.7 158.56 3.14 0.002 ZnS-S 2p [28] 164.0 162.4 161.4 157.69 3.71 0.002 CdS-S 2s [29] 226.0 224.7 223.8 220.66 3.14 0.001 ZnS-S 2s [28] 229 [75] 284.20 [71] 284.30 [5,74] 284.35 [76] 284.45 [77] 283.50-289.30 [78][79][80] z = 0 and 12 correspond to an isolated C atom and a C atom in the diamond bulk, respectively. z = 2, 3, 4, and 5.335 correspond to the atomic CN of graphene/CNT edge, graphene interior, diamond surface and bulk graphite, respectively Figure 16.11 plots CN dependence of the C1s energy E 1s (z) of carbon allotropes.…”