An efficient perovskite solar cell with symmetrical Zn() phthalocyanine infiltrated buffering porous AlO as the hybrid interfacial hole-transporting layer

A new Zn( ii ) phthalocyanine (Pc) based low bandgap HTM is introduced for perovskite solar cells. Steady state and time-resolved photoluminescence (PL) measurements indicated an evenly matched hole extraction efficiency between sym -HTPcH and spiro-OMeTAD . On account of the low film quality and resulting high recombination, Zn( ii ) Pc normally cannot work as an effective HTM. We adopted insulating Al 2 O 3 for the infiltration of sym -HTPcH to form a hybrid interfacial buffer layer, affording perovskite solar cells (PSCs) with an average PCE value of up to 12.3%, which is a significant improvement with respect to the control cell without the meso -Al 2 O 3 layer (4.21%) and is the highest value ever reported for Zn( ii ) phthalocyanine based devices under AM1.5G standard conditions. A hysteresis test revealed that our device structure with the new HTM exhibited a balanced charge extraction behaviour. An interfacial buffer layer made of Al 2 O 3 and sym -HTPcH facilitates perovskite solar cells with an average PCE value of 12.3%.