Enhanced efficiency and ambient stability of planar heterojunction perovskite solar cells by using organic-inorganic double layer electron transporting material

Abstract The optimal interface of a perovskite solar cell promotes efficient charge transport to achieve high power conversion efficiency. Tin(IV) oxide is one of the most well-known electron transport materials for perovskite solar cells. Despite tin(IV) oxide serves low hysteresis, low defect concentration and low fabrication temperature of perovskite solar cells, low conduction band edge of tin(IV) oxide limits built-in potential of the solar cell device. Here, we design an organic-inorganic double electron transporting layer by coating a 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d′]-s-indaceno[1,2-b:5,6-b′]dithiophene on tin(IV) oxide to improve the electron transporting properties perovskite solar cells. The organic-inorganic double electron transporting layer improves the interfaces of perovskite/electron transporting layer, leading to enhancement of efficiency and stability of the solar cell devices up to >16% for 200 h. This work demonstrates the feasibility of organic-inorganic double electron transport layer for high performance perovskite solar cells.