Improvement in electrical conductivity of boron-doped diamond films after hydrogen plasma and vacuum heat treatment.

• Both vacuum heat treatment and hydrogen plasma treatment improved the electrical properties of boron doped diamond. • Oxygen provides new vacancies for the addition of more boron atoms at grain boundary into crystal lattice. • Vacuum heat treatment is a facile and cheap way to improve the electrical conductivity of the boron doped diamond. The electrical conductivity of Boron-doped diamond (BDD) films prepared by the mixture of methanol/acetone/B 2 O 3 was significantly improved after hydrogen plasma and vacuum heat treatment. SEM and Raman spectroscopy were used to characterize the change of morphology and quality of BDD film after heat treatment, and the electrical properties of BDD film were determined by Hall effect. The chemical bonding states of boron atoms were analyzed by X-ray photoelectron spectroscopy. A mechanism at the origin of the improved conductivity after the heat treatments was proposed. It is oxygen that provides new vacancies for the addition of more boron atoms at grain boundary into crystal lattice, thus enhancing the electrical properties. There are different roles of oxygen in different heat treatments. [ABSTRACT FROM AUTHOR]