▎ 摘　　要

NOVELTY - The method involves providing a dry film and an inert atmosphere, and doping the inert atmosphere with an aromatic compound for dissolving the dry film. The dry film is subjected to standing treatment, heat treatment or ultraviolet light irradiation treatment under the inert atmosphere to obtain a thin film. The volume concentration of the aromatic compound in the inert atmosphere is 2.2%-5%, in the step of standing the dry film in the inert atmosphere. The aromatic compound is selected from one of chlorobenzene, bromobenzene and iodobenzene. USE - Method for preparing thin film of LED (claimed) such as quantum dot LED (QLED) and organic LED (OLED). ADVANTAGE - The film morphology of the hole functional layer is improved, the interface resistance between the hole functional layer and the light-emitting layer is reduced, the hole transport efficiency of the device is improved, and the hole transport efficiency and the electron transport efficiency of the device are effectively balanced, thus improving the optoelectronic performance and working life of the device. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a method for preparing LED; and (2) a LED. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic structural diagram of a light emitting diode. Anode (1) Light-emitting layer (3) Cathode (5) Hole injection layer (21) Hole transport layer (22)