▎ 摘　　要

Three-dimensional graphene (3D-Gr) has a unique construction and special thermal features, thus providing promising opportunities for application in thermal management devices. Herein, 2D graphene (2D-Gr) is introduced as an interfacial layer in plasma-assisted chemical vapor deposition (PACVD); then, in situ growth of 3D-Gr is achieved on a germanium (Ge) substrate. Systematic experiments are conducted to study and analyze the synthesis mechanism. Finally, the obtained 2D/3D-Gr integrations are developed for the application in high-performance thermal management. By measuring and comparing the thermal heating performance of the pure 3D-Gr device and 2D/3D-Gr device, it is determined that the combination of 3D-Gr with 2D-Gr significantly improves their thermal heating behavior, benefiting from the improved quality of 3D-Gr assisted by the 2D-Gr interfacial layer. The investigations offer an effective strategy for synthesizing high-quality 3D-Gr and 2D/3D-Gr integrations, which pave the way for the development of high-performance thermal management devices.