Stable high efficiency perovskite solar cells using vacuum deposition

A vacuum deposition process is developed to fabricate high efficiency perovskite solar cells with high stability using alternating layer-by-layer vacuum deposition. The power conversion efficiencies for the planer device is as high as 19.4% on rigid glass substrate and 15.1% using flexible polymeric substrate, both are the highest reported to date for their respective categories. Meanwhile, the devices shows very good stability over long term exposure in ambient with very low degradation.