Preparation and electrochemical properties of boron-doped polycrystalline diamond film with five-fold twin structure

In this study, boron-doped polycrystalline diamond (BDD) films were deposited on 6-inch silicon wafer by using microwave plasma chemical vapor deposition (MPCVD). Mixed gas containing hydrogen, methane, and diborane was used as precursor and the wafer temperatures were set at 750 degrees C, 850 degrees C and 950 degrees C, respectively. Five-fold twin structures were observed in the samples prepared at 850 degrees C and they promote the increase of surface roughness. Furthermore, these twin structures may lead to the increase of boron atoms at the surface, which was verified by first-principles calculation. BDD film that contains five-fold twin structures has higher Hall mobility, lower electrical resistivity and larger hole carrier concentrations at room temperature. Besides, reactive red X-3B (200 mg/L) was fully degraded by BDD electrodes at current density of 100 mA/cm2 within 40 min using NaCl as supporting electrolyte. Overall, BDD film electrodes prepared by appropriate methods contain a large quantity of five-fold twin structures surface have excellent electrochemical properties and thereby demonstrate potential as a promising waste water degradation material.

Automated summary

In this study, boron-doped polycrystalline diamond films were deposited on silicon wafers by using MPCVD. Films with five-fold twin structures exhibited higher Hall mobility, lower electrical resistivity and larger hole carrier concentrations, showing excellent electrochemical properties. Furthermore, these films showed promising potential as wastewater degradation materials.