Alternating precursor layer deposition for highly stable perovskite films towards efficient solar cells using vacuum deposition

An effective technique is developed to fabricate perovskite solar cells using alternating layer-by-layer vacuum deposition. The average efficiency of the planar device is 15.37% with a minimal standard deviation of +/- 0.37% and the best efficiency as high as 16.03%. Moreover, the device shows very good stability over 62 days with very little degradation