Subnanometer Thick Native sp2 Carbon on Oxidized Diamond Surfaces
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2025-10-01 |
| Journal | Langmuir |
| Authors | Ricardo Vidrio, Cesar Saucedo, Vincenzo Lordi, Shimon Kolkowitz, Keith G. Ray |
| Institutions | University of WisconsināMadison, Lawrence Livermore National Laboratory |
Abstract
Section titled āAbstractāOxygen-terminated diamond has a wide breadth of applications, which include stabilizing near-surface color centers, semiconductor devices, and biological sensors. Despite the vast literature on characterizing functionalization groups on diamond, the chemical composition of the shallowest portion of the surface (<1 nm) is challenging to probe with conventional techniques like XPS and FTIR. In this work, we demonstrate the use of angle-resolved XPS to probe the first ten nanometers of both oxygen and hydrogen terminated (100) single-crystalline diamond grown via chemical vapor deposition (CVD). With the use of consistent peak-fitting methods, the peak identities and relative peak binding energies were identified for sp<sup>2</sup> carbon, ether, hydroxyl, carbonyl, and C-H groups for both of these diamond surface terminations. For the oxygen-terminated sample, we also quantified the thickness of the sp<sup>2</sup> carbon layer situated on top of the bulk sp<sup>3</sup> diamond bonded carbon to be 0.3 Ā± 0.1 nm, based on the analysis of the Auger electron spectra and D-parameter calculations. These results indicate that the majority of the oxygen is bonded to the sp<sup>2</sup> carbon layer on the diamond, and not directly to the sp<sup>3</sup> diamond bonded carbon.