Characterization of carbon and carbon nitride thin films using time-of-flight secondary-ion-mass spectrometry

Abstract

A methodology for quantitative measurement of nitrogen and hydrogen atomic composition of thin carbon nitride film using time-of-flight secondary-ion-mass spectrometry is demonstrated. The nitrogen and hydrogen compositions of the film are determined by the selected ion fragment intensity ratios ICN−/IC2− and IC2H−/IC2− measured in the negative-ion-mass spectrum of the film, respectively. Absolute values for hydrogen and nitrogen atomic compositions are extracted by calibration with nuclear reaction analysis and hydrogen forward scattering methods. The measured ion fragment mass intensities were also used to characterize the structure of the carbon nitride films. The results are compared with those measured from x-ray photoemission spectroscopy.

From Linear Molecular Chains to Extended Polycyclic Networks: Polymerization of Dicyanoacetylene

“…Furthermore, larger C x N y fragments with high nitrogen content are also observed. These results confirm the formation of an extended carbon–nitrogen network consisting predominantly of carbon–nitrogen and carbon–carbon bonds and are similar to previously reported results for carbon nitride thin films . In addition, the negative spectrum shows a fragmentation pattern similar to that of the TOF-SIMS spectrum of melamine, but with lower hydrogen content (Figure S7).…”

“…However, graphitic surfaces do exhibit characteristic fragmentation patterns in the negative ion spectrum that consist of a series of prominent C x H y peaks with low hydrogen content. 112 The negative ion spectrum of HOPG (as shown in Figure S6 ), and hydrogenated ions with low H content (such as CH − and C 2 H − ). Furthermore, larger C x N y fragments with high nitrogen content are also observed.…”

“…The N 1s core-level region (Figure b) was deconvoluted into two different Gaussian components located at 398.5 and 400.3 eV, which are consistent with the general N 1s features reported for amorphous carbon nitride and N-doped graphene. − The most intense feature at 398.5 eV is attributed to “pyridinic-type” local environments, whereas the less-intense feature at 400.3 eV is attributed to “pyrrolic-type” environments. We note that while this nomenclature is common in the XPS literature, these terms do not explicitly mean pyridine or pyrrole but refer to whether the nitrogen lone pair participates in the π system. − We were unable to resolve the small contribution from unreacted nitrile groups or any fraction of sp 3 nitrogen atoms. Analysis of structures produced by MD simulations indicates that approximately 46% of the N atoms can be classified as pyridinic (2-fold-coordinated), 29% as pyrrolic (3-fold-coordinated with short CN bonds), 19% as sp 3 (3-fold-coordinated with long C–N bonds), and 6% as sp.…”

“…The mass spectra of graphitic materials, such as highly oriented pyrolytic graphite (HOPG), do not contain monomeric molecular ions owing to their extended structure. However, graphitic surfaces do exhibit characteristic fragmentation patterns in the negative ion spectrum that consist of a series of prominent C x H y peaks with low hydrogen content . The negative ion spectrum of HOPG (as shown in Figure S6) exhibits features associated with C – , CH – , C 2 – , C 2 H – , C 3 – , C 4 – , C 5 – , and C 6 – .…”

Rheology of perfluoropolyether lubricants

“…We examine monodisperse difunctional derivatives for Formblin Z (i.e., Zdol and ZdolTX [3], [5]). The type of PFPE Zdol has a molecular architecture: --and is a random copolymer.…”