Investigating the energetic band diagrams of oxygen-terminated CVD grown e6 electronic grade diamond

Oxygen-terminated type Ila (OT-Ila) diamond with oxygen suspended in the form of a ketone bond (C=O) was synthesized via acid treatment. The Fermi level at 3.23 eV below the conduction band minimum for the OT-Ila diamond surface was measured experimentally, while that at 0.97 eV for the bulk was calculated theoretically. An acceptor model of the surface states was developed, employed, and combined with an upward-bending band diagram to compensate this energetic band difference between the surface and bulk of OT-Ila diamond. A Schottky barrier height of 3.15 eV between gold and the OT-Ila diamond was also measured. In addition, we also inferred the downward-bending band diagram for the surface of oxygen-terminated p-type diamond doped with boron. This work complements the semiconductor theory concerning diamond and will be helpful to analyze and improve the performance of devices based on oxygen-terminated diamond. (C) 2020 Elsevier Ltd. All rights reserved.