Liquid Crystal Molecule as “Binding Agent” Enables Superior Stable Perovskite Solar Cells with High Fill Factor

In article no. 1900125, Guokun Ma, Hao Wang, and co‐workers use liquid crystal (LC) molecule (4'‐heptyl‐4‐biphenylcarbonitrile) as a binding agent to connect the grain boundaries of perovskites. After treatment with the LC, perovskite crystal growth orientation can be controlled and the electron transport process is accelerated. Remarkably, the LC greatly contributes to the environmental stability of the devices.