▎ 摘　　要

NOVELTY - The process of producing electrical potential difference between two terminals, comprises illuminating a thin layer of graphene electrically connected to the terminals using an infrared electromagnetic radiation that generates a bandgap in the graphene layer for creating a photovoltaic effect and producing an electrical potential difference between the terminals. The thin layer of graphene is deposited on a transparent substrate forming a glazing for producing a potential difference in response to the glazing by sunlight, and on a photovoltaic element. USE - The process is useful for producing electrical potential difference between two terminals of a semiconductor device such as a photovoltaic cell, which is useful in buildings or vehicles. ADVANTAGE - The process is capable of simply and economically producing electrical potential difference between two terminals of the semiconductor device. DETAILED DESCRIPTION - The process of producing electrical potential difference between two terminals, comprises illuminating a thin layer of graphene electrically connected to the terminals using an infrared electromagnetic radiation that generates a bandgap in the graphene layer for creating a photovoltaic effect and producing an electrical potential difference between the terminals. The thin layer of graphene is deposited on a transparent substrate forming a glazing for producing a potential difference in response to the glazing by sunlight, and on a photovoltaic element capable of generating a potential difference in response to its lighting by visible radiation. The thin layer of graphene and photovoltaic element are connected so that the potential difference generated by the thin layer in response to its lighting is added to the potential difference generated by the photovoltaic element in response to its lighting. The process further comprises connecting the terminals to an electrical circuit to generate an electrical signal having a characteristic dependent of an infrared radiation intensity to which the sample of graphene is subjected, and quantifying the responsiveness of the graphene for determining the number of monatomic layers in the part of the graphene illuminated by infrared radiation.