▎ 摘　　要

NOVELTY - The sensor has an N-type graphene structure (3) formed by laser induction in a first preset temperature range. A P-type graphene structure (5) is formed by laser-induced calcination in a second predetermined temperature range. A surface of the N-type graphene structure and the P-type graphene structure is deposited with metal particles (4). The N-type graphene structure and the P-type graphene structure are oppositely arranged to each other and conducted with each other by a butting end. A middle part of a longitudinal N-type connecting strip is electrically connected with a first lead terminal (2). A middle part of a longitudinal P-shaped connecting strip is electrically connected with a second lead terminal (6). USE - Laser-induced graphene based P-N junction hydrogen sensor. ADVANTAGE - The sensor has simple processing technique, low cost, high flexibility, portable, and easy mass production, and enhances the selectivity of the hydrogen by inducing the micro-nano structure of the graphene and the enhanced effect generated in the material by laser, and has high selectivity for hydrogen, and can be arranged at any position through the flexible substrate according to the detection requirement, flexible and wearable, and wide application scene. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a laser-induced graphene based P-N junction hydrogen sensor preparation method. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a laser-induced graphene based P-N junction hydrogen sensor. 1Represents polyimide film 2Represents first wire terminal 3N-type graphene structure 4Represents metal particles 5P-type graphene graphene structure 6Represents second wire terminal