▎ 摘　　要

NOVELTY - An optical sensor (10) comprises a field-effect transistor (20) containing a graphene channel (26), and light-absorption layer (40) formed on a surface of the channel. The light-absorption layer comprises nitrogen functionalized-nanographene. The nitrogen-functionalized nanographene comprises nanographene, pi -conjugated nitrogen functional groups introduced into the nanographene and semiconductor having band gap of more than 0 eV. The lowest energy unoccupied molecular orbital level difference or highest occupied molecular orbital level difference of the graphene is 2 eV or less. USE - Optical sensor is used for detecting position and movement of target component. ADVANTAGE - The optical sensor has high photoconductive gain, and responds in the near infrared region from ultraviolet light. The nitrogen-functionalized nanographene does not contain toxic elements, and has long carrier lifetime. DETAILED DESCRIPTION - An optical sensor comprises a field-effect transistor containing a graphene channel and light-absorption layer formed on a surface of the channel. The graphene contains semimetals having band gap of 0 eV. The light-absorption layer comprises nitrogen functionalized-nanographene. The nitrogen-functionalized nanographene comprises nanographene, pi -conjugated nitrogen functional groups introduced into the nanographene and semiconductor having band gap of more than 0 eV. The lowest energy unoccupied molecular orbital level difference or highest occupied molecular orbital level difference of the graphene is 2 eV or less. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional schematic view of the optical sensor. Optical sensor (10) Field-effect transistor (20) Conductive substrate (22) Graphene channel (26) Light-absorption layer (40)