Printable SnO2 cathode interlayer with up to 500 nm thickness-tolerance for high-performance and large-area organic solar cells

The printable electrode interlayer with excellent thickness tolerance is crucial for mass production of organic solar cells（OSCs）by solution-based print techniques. Herein, high-quality printable SnO;films are simply fabricated by spin-coating or bladecoating the chemical precipitated SnO;colloid precursor with post thermal annealing treatment. The SnO;films possess outstanding optical and electrical properties, especially extreme thickness-insensitivity. The interfacial electron trap density of SnO;cathode interlayers（CILs） are very low and show negligible increase as the thicknesses increase from 10 to 160 nm,resulting in slight change of the power conversion efficiencies（PCEs） of the PM6:Y6 based OSCs from 16.10% to 13.07%. For blade-coated SnO;CIL, the PCE remains high up to 12.08% even the thickness of SnO;CIL is high up to 530 nm. More strikingly, the large-area OSCs of 100 mm;with printed SnO;CILs obtain a high efficiency of 12.74%. To the best of our knowledge, this work presents the first example for the high-performance and large-area OSCs with the thickness-insensitive SnO;CIL.