▎ 摘　　要

NOVELTY - Single crystal diamond epitaxial growth based on an iridium-graphene structured buffer layer, comprises preparing a layer of iridium-nickel composite patterned transition layer on the surface of a smooth diamond self-supporting substrate, and then vacuum annealing, as a result, diamond undergoes a phase change catalyzed by nickel, carbon dissolves in the nickel and precipitates on the surface to form grapheme, using iridium-graphene composite patterned substrate to eliminate lattice mismatch and thermal expansion mismatch, at the same time, performing vacuum stress relief annealing to promote the rearrangement of iridium atoms, forming a single orientation while forming sub-surface carbon atom enrichment, and achieving the nucleation and growth of single crystal diamonds by chemical vapor deposition. USE - The method is useful for single crystal diamond epitaxial growth by iridium-graphene structured buffer layer. ADVANTAGE - The method realizes the preparation of large-size and high-quality self-supporting single crystal diamond.