▎ 摘　　要

NOVELTY - A transfer-free method for producing graphene thin film is performed by (A) forming titanium buffer layer on target substrate; and (B) growing graphene thin film on titanium buffer layer, where the entire steps throughout (A) to (B) are performed in an oxygen-free atmosphere. USE - A transfer-free method for producing graphene thin film. ADVANTAGE - In the transfer-free method, the buffer layer does not need to be removed, because the mechanical, electrical, and optical properties of a substrate or a graphene layer are not impaired by the buffer layer. The method allows for production of defect-free, monocrystalline graphene thin film over a large area on a target substrate without changing the transparency and electrical properties of the target substrate, producing good-quality graphene. Furthermore, graphene with excellent crystallinity can be grown even when the temperature of the target substrate is less than or equal to 400 degrees C, particularly less than or equal to 150 degrees C, allowing for the use of a flexible substrate, providing a flexible device or a transparent electrode. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for transfer-free method for fabricating an electronic device comprising a graphene thin film, which involves producing graphene thin film via steps (A) and (B), and (C) fabricating an electrical device by using the target substrate.