Ultrathin boron-doped diamond – surface-wave-plasma synthesis of semi-conductive nanocrystalline boron-doped diamond layers at low temperature

Abstract

The pursuit of cost-effectiveness has prompted the global scientific community to develop innovative materials and techniques that either meet or surpass essential functionality and performance requirements. In this context, the ongoing development of boron-doped diamond (BDD) electrodes has been demonstrated to significantly contribute to the advancement of several prospective applications, such as electroanalysis, electrosynthesis and electrochemical treatment. Nevertheless, in order for BDD electrodes to compete with inexpensive alternatives, the fabrication of BDD electrodes should be performed in a cost-effective and simple manner. In this work we report on the synthesis of ultrathin boron-doped diamond layers using a surface-wave-plasma (SWP) technique which enables a facile fabrication route for diamond coatings. As SWP synthesis allows for fabrication of BDD at much lower temperatures, when compared to conventional synthesis techniques, ultrathin BDD layers were prepared at 500 °C. A primary focus was given to the systematic optimization of CO₂ concentration in the gas-phase to target BDD layers of moderate semi-conductive electrical characteristics, which are of interest for several applications. Considering the collective research efforts on the development of cost-effective materials and strategies, BDD layers were fabricated in the ultrathin form that supports not only the reduction in fabrication time and energy consumption, but also offers a versatile functional material that could benefit electro-optical and electrochemical applications.