Growth behavior of diamond films on graphite using solid-state boron sources

Diamond films were grown on graphite substrates by microwave-assisted chemical vapor deposition using solid-state boron sources as an alternative to conventional gaseous dopants. This non-gaseous route modifies the local growth conditions through direct contact between boron-containing regions and graphite during the early stages of deposition. Structural, spectroscopic, and morphological analyses were performed to investigate diamond film growth behavior. Raman spectroscopy revealed spectral features consistent with boron-related modifications in the diamond lattice, while X-ray diffraction confirmed the formation of microcrystalline diamond without detectable secondary crystalline phases. Scanning electron microscopy observations and complementary focused ion beam inspection indicated that solid-state boron sources modified the surface morphology and the graphite–diamond interfacial region, leading to rough lamellar and wall-like features in selected boron-containing samples. The results indicate that the physical state and distribution of solid-state boron influence diamond film growth and interfacial morphology on graphite substrates, providing an alternative route for boron-assisted chemical vapor deposition.