Coexistence of carbonyl and ether groups on oxygen-terminated (110)-oriented diamond surfaces

Abstract Diamond-based materials have unique properties that are exploited in many electrochemical, optical, thermal, and quantum applications. When grown via chemical vapor deposition (CVD), the growth rate of (110) face is typically much faster than other two dominant crystallographic orientations, (111) (100). As such, achieving sufficiently large-area high-quality (110)-oriented crystals challenging requires post-growth processing surface. Whilst CVD confers hydrogen terminations on diamond surface, majority procedures render surface oxygen-terminated, which turn impacts material. Here, we determine oxygenation state using a combination density functional theory calculations X-ray photoelectron spectroscopy experiments. We show 0–1000 K temperature range, phase diagram dominated by highly stable coexisting adjacent carbonyl ether groups, while stability peroxide groups increases at low temperatures high pressures. propose mechanism for formation hybrid carbonyl-ether rationalize its stability. further corroborate our findings comparing simulated core-level binding energies with experimental data highest-quality crystal reported to date.