Dontschuk, N.N.DontschukRodgers, L.V.H.L.V.H.RodgersJYH PIN CHOUEvans, D.A.D.A.EvansO’Donnell, K.M.K.M.O’DonnellJohnson, H.J.H.J.JohnsonTadich, A.A.TadichSchenk, A.K.A.K.SchenkGali, A.A.Galide Leon, N.P.N.P.de LeonStacey, A.A.Stacey2024-09-182024-09-182023https://www.scopus.com/record/display.uri?eid=2-s2.0-85177202975&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/721389Article number 045901Identifying the surface chemistry of diamond materials is increasingly important for device applications, especially quantum sensors. Oxygen-related termination species are widely used because they are naturally abundant, chemically stable, and compatible with stable nitrogen vacancy centres near the diamond surface. Diamond surfaces host a mixture of oxygen-related species, and the precise chemistry and relative coverage of different species can lead to dramatically different electronic properties, with direct consequences for near-surface quantum sensors. However, it is challenging to unambiguously identify the different groups or quantify the relative surface coverage. Here we show that a combination of x-ray absorption and photoelectron spectroscopies can be used to quantitatively identify the coverage of carbonyl functional groups on the { 100 } diamond surface. Using this method we reveal an unexpectedly high fraction of carbonyl groups ( > 9%) on a wide range of sample surfaces. Furthermore, through a combination of ab initio calculations and spectroscopic studies of engineered surfaces, we reveal unexpected complexities in the x-ray spectroscopy of oxygen terminated diamond surfaces. Of particular note, we find the binding energies of carbonyl-related groups on diamond differs significantly from other organic systems, likely resulting in previous misestimation of carbonyl fractions on diamond surfaces. © 2023 The Author(s). Published by IOP Publishing Ltd.DFTdiamond surface for NV centresNEXAFSoxygen terminated diamondsurface spectroscopyXPSjournal article10.1088/2633-4356/ad001b2-s2.0-85177202975