Chemical vapor deposited diamonds on Re substrate for the application of field emission

Boron-doped diamond (BDD) films were deposited on rhenium substrates using methane/hydrogen as reactant gases by hot filament chemical vapor deposition (HFCVD). The morphology, band structures and crystalline structure of the BDD films were characterized by the scanning electron microscope (SEM), Raman spectroscopy and X-ray diffractometer (XRD), respectively. The effects of the pre-treated on nucleation and quality of the diamond film were investigated. The mixture of sulfur acid and nitric acid enhanced diamond nucleation much more greatly than that of single acid. The highly boron-doped diamond films were deposited on rhenium substrate. The field emission characteristics of these films were analyzed. The minimum resistivity of doped diamond films reached 10− 2 Ω cm. Field emission studies revealed that the BDD film grown on rhenium substrate had the low threshold field (3.3 v/μm).