▎ 摘　　要

NOVELTY - Preparing graphene crystal films comprises e.g. (i) taking a vacuum chamber provided with an X-Y worktable and electron gun, the metal substrate covered with a carbon polymer film is installed on the X-Y workbench and located directly below the beam outlet of the electron gun and the metal substrate is insulated from the X-Y workbench and connected to the X-Y workbench through the current sensor, and the X-Y workbench is grounded; (ii) adjusting the position of the X-Y workbench so that the beam vertical output point of the electron gun is located in the beam intensity calibration hole in the beam calibration area on the metal substrate; and (iii) setting the working voltage Uhv and beam current Ib of the electron gun, and adjusting initially the focusing current If of the electron gun, setting the beam spot diameter D to a given range, recording the focus current and turning off the beam output of the electron gun. USE - The method is useful for preparing graphene crystal films. ADVANTAGE - The method: produces graphene crystal film in a vacuum environment without affecting by other impurity gases with better quality and high energy conversion efficacy when electrons interact with materials; and does not need to coat photosensitive materials on the material surface; and is simple. DESCRIPTION OF DRAWING(S) - The drawing shows the schematic representation of flow chart of preparing graphene crystal films. (Drawing includes non-English language text).