▎ 摘　　要

NOVELTY - The device has first electrode (E10) connected to first region of a graphene layer (GP10). Second electrode (E20) is in spatial correspondence to second region of the graphene layer. A functional layer (F10) is formed between the graphene layer and the second electrode, and includes nonvolatile memory characteristics and piezoelectric characteristics. A gate (G10) faces the functional layer with the graphene layer. A gate insulation layer (GI10) is formed between the graphene layer and the gate. The functional layer comprises an ambipolar semiconductor. USE - Graphene device i.e. multi-functional device (claimed), for use in an electronic apparatus e.g. transistor, electronic circuits, logic devices and a semiconductor device. ADVANTAGE - The functional layer provides a property of nonvolatile memory characteristics, piezoelectric characteristics, and optoelectronic conversion characteristics. The device provides a function of a switching device and optoelectronic conversion characteristics, nonvolatile memory characteristics, and piezoelectric characteristics. DETAILED DESCRIPTION - The functional layer comprises a resistance change material, a phase change material, a ferroelectric material, a multiferroic material, multistable molecule, a piezoelectric material, a chalcogenide material, a perovskite material, a two-dimensional (2D) material and an organic material. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a graphene device. Electrodes (E10, E20) Functional layer (F10) Gate (G10) Gate insulation layer (GI10) Graphene layer (GP10)