While metal halide perovskite solar cells (PSCs) presently attract enormous research interest because of their high solar to electric power conversion efficiency (PCE) and low fabrication costs, their practical development is hampered by difficulties to reach high performance on large size devices. Here we introduce a simple vacuum-flash solution processing method to obtain shiny, smooth and crystalline perovskite films of high electronic quality over large areas. This enables us to fabricate solar cells with an aperture area exceeding 1 cm2 showing a maximum efficiency of 20.5% and a certified PCE of 19.6. This exceeds by far the current certified record of 15.6% for PSC of similar size. We demonstrate that the reproducibility of the method is excellent and that the cells show virtually no hysteresis. The success of this new approach paves the way to realize highly efficient large-area PSCs for practical deployment.

Science 09 Jun 2016:
DOI: 10.1126/science.aaf8060

http://science.sciencemag.org/content/early/2016/06/08/science.aaf8060.long