Extremely high negative electron affinity of diamond via magnesium adsorption

Kane Michael O'Donnell, Mark Thomas Edmonds, Anton Tadich, Lars Thomsen, Alastair Stacey, Alex Schenk, Christopher Ian Pakes, Lothar F Ley

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39 Citations (Scopus)


We report large negative electron affinity (NEA) on diamond (100) using magnesium adsorption on a previously oxygen-terminated surface. The measured NEA is up to (−2.01±0.05) eV, the largest reported negative electron affinity to date. Despite the expected close relationship between the surface chemistry of Mg and Li species on oxygen-terminated diamond, we observe differences in the adsorption properties between the two. Most importantly, a high-temperature annealing step is not required to activate the Mg-adsorbed surface to a state of negative electron affinity. Diamond surfaces prepared by this procedure continue to possess negative electron affinity after exposure to high temperatures, air, and even immersion in water.
Original languageEnglish
Article number035303
Pages (from-to)1-7
Number of pages7
JournalPhysical Review B
Issue number3
Publication statusPublished - 2015

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