To fabricate graphene based electronic and optoelectronic devices, it is highly desirable to develop a variety of metal‐catalyst free chemical vapor deposition (CVD) techniques for direct synthesis of graphene on dielectric and semiconducting substrates. This will help to avoid metallic impurities, high costs, time consuming processes, and defect‐inducing graphene transfer processes. Direct CVD growth of graphene on dielectric substrates is usually difficult to accomplish due to their low surface energy. However, a low‐temperature plasma enhanced CVD technique could help to solve this problem. Here, the recent progress of metal‐catalyst free direct CVD growth of graphene on technologically important dielectric (SiO₂, ZrO₂, HfO₂, h‐BN, Al₂O₃, Si₃N_4, quartz, MgO, SrTiO_3, TiO₂, etc.) and semiconducting (Si, Ge, GaN, and SiC) substrates is reviewed. High and low temperature direct CVD growth of graphene on these substrates including growth mechanism and morphology is discussed. Detailed discussions are also presented for Si and Ge substrates, which are necessary for next generation graphene/Si/Ge based hybrid electronic devices. Finally, the technology development of the metal‐catalyst free direct CVD growth of graphene on these substrates is concluded, with future outlooks.

Graphene-on-silicon (Gr–Si) heterojunction solar cells have recently attracted significant attention as promising candidates for low-cost photovoltaic applications. However, the power conversion efficiency of Gr–Si solar cells is generally smaller than 4% without chemical doping treatments. It is mainly limited by the low work function of Gr and high density defect states at the Gr–Si interface. Here, we have reported a new structure of Gr–Si solar cells by introducing a graphene oxide (GO) interlayer to engineer the Gr–Si interface for improving device performance. It is found that the GO interlayer can effectively increase open circuit voltage and meanwhile suppress the interface recombination of solar cells. As a result, a maximum efficiency of 6.18% can be achieved for the Gr/GO/Si solar cells, which is a new record for the pristine monolayer Gr–Si solar cell reported to date. Further, it is clarified that the Gr/GO/Si solar cell is significantly more stable than the Gr–Si solar cell with chemical doping. These results show a new route for fabricating efficient and stable chemical-doping-free Gr–Si solar cells.