NOVELTY - An electronic device (200) comprises: anode (202); cathode structure (214) including single layer of graphene, and electron acceptor material (210) in contact with single layer of graphene (212); and electronic element coupled between anode and cathode structure.    USE - An electronic device selected from tandem photocell, photodiode, photomultiplier, and touch screen user interface (claimed).    ADVANTAGE - The electronic device, particularly optoelectronic device, includes graphene i.e. two-dimensional crystalline form of carbon, in cathode structure along with electron acceptor material in contact with graphene layer; where graphene provides high transparency, conductivity flexibility, and elemental abundance, and provides excellent replacement for transparent conducting oxide electrodes. Graphene has characteristics favorable for optoelectronic device integration, such as high room temperature carrier mobilities, high current densities, very high transparency, and mechanical flexibility. In prior art approach of using graphene electrodes is limited by its use as anode, as work function of graphene lends itself most readily to hole injection, while its intrinsic physical fragility constrains integration processes. Most devices are built from anode up, because it is difficult to deposit high-quality graphene on top of semiconducting materials as cathode. The improved electronic device includes integration of graphene onto top of device, as cathode, where graphene can be either grown or transferred onto soft stamp material, which can then be laminated onto nearly complete optoelectronic device. Thus electronic devices that utilize graphene provide improvements in manufacturing and device performance. Further, in many electronic devices, performance of device is affected by work function of cathode structure, such as in organic photovoltaic device, in order to form ohmic contact with semiconducting region, work function of electrode such as an anode or cathode structure is desired that is close to or matching work function of semiconducting region. The electronic devices comprising cathode having graphene layer, are configured along with electron acceptor material that modifies work function of layer of graphene from 4.6 eV to 4.3 eV.    DETAILED DESCRIPTION - An electronic device (200) comprises: anode (202); cathode structure (214) including single layer of graphene, and electron acceptor material (210) in contact with single layer of graphene (212); and electronic element coupled between anode and cathode structure. The electron acceptor material modifies work function of layer of graphene from 4.6 eV to 4.3 eV. The electronic device is configured as tandem photocell, and further includes shared graphene layer separating top photovoltaic device and bottom photovoltaic device in tandem photocell. The electronic device further includes second layer of graphene over single layer of graphene to form bi-layer structure. The electronic element includes liquid crystal element; or is optically active element, where optically active element includes organic photovoltaic region (206, 208), or organic light emitting element. The organic photovoltaic element includes heterojunction photovoltaic region, and electron acceptor material is located between heterojunction photovoltaic region and at least one layer of graphene. The anode includes single layer of graphene, or bi-layer graphene structure. An INDEPENDENT CLAIM is included for method for making the electronic device involving: forming electronic element over anode; and forming cathode structure over electronic element by selecting desired cathode work function, and coupling single layer of graphene to electron acceptor material to contact dope single layer of graphene to modify work function of single layer of graphene towards desired cathode work function.    DESCRIPTION OF DRAWING(S) - The figure shows the optoelectronic device.    Organic photovoltaic device (200)    Bottom of device stack (201)    Indium tin oxide anode (202)    Poly(3,4-ethylenedioxythiophene) layer (204)    Organic photovoltaic element including heterojunction photovoltaic region of copper phthalocyanine layer (206)    Organic photovoltaic element including heterojunction photovoltaic region of C60 layer (208)    Electron acceptor material layer (210)    Graphene layer (212)    Top of device stack (213)    Graphene cathode structure (214)    Chart of work functions in components of organic photovoltaic device (220)