NOVELTY - Forming (M1) graphene (G) involves providing a graphite sample (10) having atomic layers (11) of carbon; introducing a solvent (14) and ions into the spaces (9) between the atomic layers; expanding the space between the atomic layers using at least one of the solvent and the ions; and separating the atomic layers using a driving force (45) to form at least one sheet of graphene.    USE - For forming graphene, which is used to form photovoltaic devices, and solar cells to perform DNA analysis (claimed); in bioanalytics, combining high-efficiency extraction and ultrasensitive detection in the analytical protocol; to form conducting sheets that are opaque (e.g. from paper) or transparent (e.g. from plastic); for other electrical, optical and biological applications; for in situ inspection of pesticide residues on food/fruit; and in automobile exhaust purifier.    ADVANTAGE - The method is high-yield oxidation-free method of forming graphene flakes directly from graphite that bypasses oxidation treatment, i.e. without forming graphene-oxide (GO); and is time-consuming and add significant cost to the analyses. The graphene fabricates nanocrystal/graphene heterojunction solar cell, which can be made to have record power conversion efficiency (e.g. 3.2%). The solution-based device fabrication process is low cost, scalable and has low toxicity. The catalyst graphene supports technologies that improves the catalytic activity of Pt-based catalysts to reduce the Pt usage in catalysts, thus lowers fuel-cell cost. The method produces graphene/oxide heterojunctions with high performance and efficiency for a wide range of applications.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for forming (M2) graphene from a graphite sample comprising a lattice of carbon atoms that define atomic layers and a layer spacing, involving intercalating organic molecules and salts (12) into the carbon atom lattice; expanding the layer spacing using at least one of the organic molecules and ions provided by the salts; and exfoliating at least one carbon atomic layer from the graphite sample using at least one driving process selected from an electrochemical process, thermal process, microwave process, solvothermal process, sonochemical process (40) and an acoustic process.    DESCRIPTION OF DRAWING(S) - The figure shows schematic overview of graphite exfoliation process to form few-layer graphene G.    Graphene (G)    Spaces (9)    Graphite sample (10)    Atomic layers (11)    Salts (12)    Solvent (14)    Sonochemical process (40)    Driving force (45)    Solar cell active layer (60)    Solar cells. (70)