The Highly Efficient Perovskite Solar Cells Prepared In Amibient Air

Recently,organic-inorganic hybrid perovskite solar cells have become a promising prospect in the field of photovoltaic cell research. During the five years from 2009 to 2014, the photoelectric conversion efficiency of perovskite solar cells was obtained from 3.5% to 20.1%. The past two years have witnessed a breakthrough of 21% of the conversion efficiency. Perovskite solar cells have been widely concerned for the high efficiency, low cost and simple fabrication process in the photovoltaic field. Currently, perovskite solar cells are basically prepared in the glove box, without which the device is almost impossible to be constructed. If the device fabricated in the glove box was exposed to amibient air, it would break down after 2-3 days of aging. So this paper aimed to study the highly efficient perovskite solar cells prepared in amibient air, which could make it possible that not only a certain efficiency could be ensured, but also the corresponding life. Then much contribution will be done for the commercial development of the perovskite solar cells.Based on the structure of mesoporous perovskite solar cells, this paper has done the following three aspects:(1) A mesoporous perovskite solar cell with carbon as the counter electrode was prepared. The difference between the cell and the conventional mesoporous perovskite solar cell was that the hole transport layer was free, so the producing cost would be significantly reduced. In addition, the carbon-electrode was printed up and easy to be operated. The best photoelectric conversion efficiency of a battery device could be up to 9.32%.(2) A perovskite solar cell device with a complete structure was prepared by two-step method and one-step method in the amibient air. One-step method consists of two methods that the former one was anti-solvent method and the latter one was vacuum-flash method. In this paper,it was found that the efficiency of photoelectric conversion was 14.84%, and the efficiency range of the device was very narrow,which was the highest in the battery device prepared by the new formula combined with the vacuum-flash method. The efficiency of battery, which was prepared by the vacuum-flash method and not packaged in the amibient air after 1000 hours of aging,was reduced by only about 2%. All of this turned out that the vacuum-flash preparation method was the best.(3) The mesoporous TiO2 layer with different thickness was controlled and then what we found was that the thickness of the mesoporous layer had a great influence on the efficiency of the device.