Growth of III-N/graphene heterostructures in single vapor phase epitaxial process

•Carbon deposition on sapphire by propane pyrolysis in III-N MOVPE reactor is studied.•Conditions, resulting in graphene layers formation are optimized.•Graphene stability in various reactor conditions is studied.•III-N structures growth on graphene in a single epitaxial process is developed.•Large-area defoliation of the formed III-N structures is demonstrated. We investigated the growth of III-N/graphene heterostructures as a single process in a MOVPE reactor. Raman spectra revealed that graphene can be successfully deposited on sapphire substrate by propane pyrolysis if temperature exceeds 1060 °C and hydrogen is used as a carrier gas. GaN epitaxial layers and heterostructures on such graphene using both high-temperature AlN buffer layer and low-temperature GaN nucleation layer was demonstrated. Analysis of surface morphology and X-Ray diffraction curves indicate that GaN quality depends on graphene thickness. Use of copper electroplated Ni-based contact layer combined with thermal shock allows exfoliation of large-area III-N LED structures from sapphire.