Hybrid lead-halide perovskite solar cells(PSCs)are presently under intense investigation owing to their high efficiency with low processing cost.Further cost reductions are possible by replacing the noble metal counter electrode with a printable carbon electrode to fabricate fully printable perovskite solar cells.[1] The composition of the perovskite infiltrated in the mesoporous structure may be important,which will extremely affect the power conversion efficiency as well as other intrinsic charge responses in the device.Specifically,a mixture of multiple halogen elements in hybrid perovskites can bring several advantages,such as a tuned band gap,enhanced stability,and improved carrier transport.