Interfacial band bending and suppressing deep level defects via Eu-MOF-mediated cathode buffer layer in an MA-free inverted perovskite solar cell with high fill factor

To solve the problem of deep-level surface defects, lead thiocyanate is utilized in FACsPbI 3 absorber. Additionally, a novel Eu-MOF was integrated into the buffer layer to regulate band alignment while impeding the hole backflow at the back cathode.