▎ 摘　　要

NOVELTY - A transparent conductive film (F1) comprises: graphene platelets (301) overlapping one another to form a multilayer structure. USE - As transparent conductive film, for forming transparent conductive film-on-substrate, for electronic device selected from flat panel display device, touch panel, and photovoltaic cell (claimed). ADVANTAGE - The conductive film comprising overlapping graphene platelets to form multilayer structure provides an alternative to indium tin oxide (ITO) transparent conductive film; where conventionally ITO is widely used as material for transparent conductive films and contains tin oxide (5-10 mass%), where since indium is rare metal, its availability is easily affected by market value and there is concern over its future availability. The conductive film comprising graphene platelets is formed of inexpensive carbon materials, instead of rare metals such as indium. The transparent conductive film has low electrical resistivity of less than or equal to 1x 10-6 ( Omega m) and a light transmission at a wavelength of 550 nm of greater than or equal to 80%. It is revealed that electrical resistivity of wiring decreases with increasing size of graphene platelet, and light transmission increases with decreasing number of layers. For a graphene transparent conductive film to achieve conventional properties of ITO electrical resistivity of less than or equal to 1x 10-6 ( Omega m) and light transmission at 550 nm of greater than or equal to 80%, it needs to be formed of graphene platelets that are greater than or equal to 50 nm in average size and are in less than or equal to 9-ayer stack. Also, graphene platelet comprising several atomic layers is regarded as same as a single-atom graphene layer, if the total number of atomic layers of graphene platelets in the multilayer structure is less than or equal to 9. The light absorption of graphene sheet at 550 nm is 2.3%. Thus, for graphene platelets in 2-layer stack light transmission is 95.5%, and for graphene platelets in 9-layer stack it is 81.1%. Since light transmission of commercially available ITO film is typically 80% and the electrical resistivity is 1.5x 10-6 ( Omega m), the graphene platelets that are greater than or equal to 50 nm in wiring film formed of less than or equal to 9-layer stack can achieve performance comparable to that of ITO. Such performances are equal to or higher than those of conventional ITO film. Thus the graphene conductive films (or transparent electrode) can replace an ITO film. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a transparent conductive film-on-substrate comprising: a substrate and the transparent conductive film (F1) formed on the substrate, where the substrate is made of glass or plastic. DESCRIPTION OF DRAWING(S) - The figure shows a plan view of the transparent conductive film. Graphene platelets (301)