Ternary polymer solar cell

A polymer solar cell, comprising a substrate layer, a transparent conductive cathode, a cathode buffer layer, a photoactive layer, an anode buffer layer and a metal anode successively from bottom to top, wherein a non-fullerene perylene diimide (PDI) electron acceptor is introduced into the photoactive layer;

• in the photoactive layer, a ratio of a weight percentage of a polymer electron donor, a polymer electron acceptor and the non-fullerene PDI electron acceptor is 1:
• (0-1):
• (0.1-1);
• the non-fullerene PDI electron acceptor is a compound containing no fullerene group but containing PDI groups;
• the non-fullerene PDI electron acceptor comprises 2PDINB;
• an absorbing band of the 2PDINB is between 300 nm and 900 nm;
• a structural formula of the 2PDINB is:
• a preparation method of the 2PDINB comprises:
• first, making the PDI and concentrated nitric acid react in dichloromethane for 2-4 h to generate PDI with nitro groups, then refluxing the PDI with nitro groups, iron powder and concentrated hydrochloric acid in tetrahydrofuran for 30-60 min to obtain PDI with amino groups, and finally, refluxing the PDI with amino groups, terephthalaldehyde and acetic acid in ethanol for 24-30 h to obtain 2PDINB.