Photoexciton diffusion measurement method based on organic photosensitive field effect transistor

The invention discloses a photoexciton diffusion measurement method based on an organic photosensitive field effect transistor. The following technical scheme is adopted for implementation: (1) an organic photosensitive field effect transistor is prepared: a bottom grid structure is adopted, an organic functional layer, a source electrode and a drain electrode are a sandwiched structure, an organic semiconductor material with high mobility is used as a channel transport layer, the source and drain electrodes are in ohmic contact with the channel layer, the organic photosensitive material is deposited and covers the channel region and the source and drain electrodes, and the organic photosensitive field effect transistor with different thicknesses of the organic photosensitive material is prepared; (2) the photoelectric properties of the organic photosensitive field effect transistors are measured, the relationship between photocurrent and thickness of a photosensitive layer is obtained, and the photoexciton d