Fabrication of polycrystalline phosphorus-doped diamond electrodes from red phosphorus

Abstract

Polycrystalline phosphorus-doped diamond was fabricated by the quartz-tube-type microwave plasma-assisted chemical vapor deposition method. Significantly, red phosphorus was used as a source of phosphorous, instead of PH₃. Phosphorus-doped diamond electrodes with hydrogen-terminated and oxygen-terminated surfaces were investigated for the redox reactions of K₃[Fe(CN)₆] and [Ru(NH₃)₆]Cl₃. The carrier concentration was estimated as 2.1–5.3 × 10¹⁸ cm⁻³ from electrochemical impedance measurements. Polycrystalline phosphorus-doped diamond shows great promise as chemical electrode materials.