The invention discloses a
cathode interface modification material, and a
solar cell as well as a preparation method and application thereof. The
cathode interface modification material is prepared from poly [9,9-bis(3'-(N,N-dimethylamino) propyl)-2,7-
fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) and / or derivatives of the PFN. The organic
thin film solar cell comprises a top
electrode layer, a
cathode interface modification layer, a light absorption
active layer, a
hole transport layer and a bottom
electrode which are sequentially arranged in the set direction, wherein the cathode interface modification layer is prepared from the cathode interface modification material. The cathode interface modification material provided by the invention adopts the PFN with a permanent
electric dipole moment to modify the interface of a cathode of the organic
thin film solar cell, namely, a suitable
electron transport layer is inserted into the organic
thin film solar cell, so that a built-in electricfield is effectively enhanced, carrier transport is further improved, and recombination loss is reduced; the cathode interface modification material can reduce the cathode
work function, reduce the
electron injection barrier and improve the
electron injection efficiency, thereby greatly improving the luminous efficiency, service life and stability of the device, and further increasing the
cell efficiency.