LAUSR

The inorganic halide perovskite CsPbI3 has shown great promise in efficient solar cells. However, α-phase CsPbI3 is thermodynamically unstable at room temperature, limiting its applications. Herein, we have successfully fabricated highly stable all-inorganic 0D/3D Cs4Pb(IBr)6/CsPbI3−xBrx mixed-dimensional perovskite solar cells. The 0D Cs4Pb(IBr)6 phase spontaneously distributes in the 3D CsPbI3−xBrx perovskite phase and facilitates the (100) preferential crystal orientation of the CsPbI3−xBrx crystals. Due to the reasonable energy level alignment and lattice match between (040) in 0D Cs4Pb(IBr)6 and (002) in 3D CsPbI3−xBrx crystals, a 0D–3D heterojunction structure formed. The defect passivation and non-radiative recombination suppression within the films effectively promote smooth carrier transport in the perovskite solar cells, boosting the efficiency to 14.77%. The devices retained 93.9% of the initial efficiency after 60 days in a nitrogen atmosphere. Moreover, a high efficiency of 10.52% has also been achieved in the 1 cm2-large solar cells due to the high uniformity and repeatability of the 0D/3D films.