Samsung continues to show its interest in graphene for high-tech devices with its latest patent, entitled simply “display devices”. US patent number 8294972 describes a rather unusual type of screen – one that does not require a source of light.
Instead of shining light from behind to display visual information, as is commonly done, Samsung proposes an interesting approach, based on reflection of ambient light by a thin film layer on top of electrodes. The thin layer would have changing optical properties under the influence of applied electric fields. If graphene is used, its absorptance and reflectance would be changed by tuning the back gate. Supposedly, the back gate would be patterned to allow pixel-level control of the reflectivity of the graphene film. In addition, color filters would be deposited on top of the graphene to generate the RGB, with a protective layer on top of it all.
This is an unusual and interesting scheme, which raises several questions, such as how the device would perform in the dark, or what the top protective layer would be. Nevertheless, it is yet another step forward for Samsung, who seem to be ahead of everybody else in the realm of graphene-based flexible screens.