Solution-processed Fe-2-xMg(xO3) ternary oxides for interface passivation in efficient perovskite solar cells

Interface function material has been widely used to reduce interfacial potential barrier for enhanced chargedynamics and photovoltaic properties of perovskite solar cells (PSCs). Herein, ternary oxides Fe2-xMgxO3 are introduced to passivate the perovskite/SnO2 quantum dots (QDs) interface. The interaction between perovskite and Fe2-xMgxO3 could trigger a heterogeneous nucleation for the uniform perovskite photoactive layer. The flocculent Fe2-xMgxO3 also increase the interface contact with perovskite enabling more transferring channel of electron, and decrease the interface-defects with smaller the energy level offset at this interface. Such oxide bridges between perovskite and SnO2 QD could effectively enhance electron transfer. Consequently, a Fe1.84Mg0.16O3-based PSC is achieved with a champion efficiency over 21% and negligible J-V hysteresis.