Transition from Dye Sensitized Solar Cells to Halide Perovskite Solar Cells -Recent Progress and Future Perspective

<p>Pb perovskite solar cells were derived from the research on dye-sensitized solar cells. During the research progress, the process on dye-sensitized solar cells were merged with that of organic thin film solar cells to give high efficiency  solar cells. Although the Pb perovskite solar cells are prepared by printing technology at low temperature, the efficiency higher than 25 % has been reported, and is going to catch up that of single crystalline silicon solar cells prepared at 1500 °C. The research trend is to make modules with large area. However, Pb ions containing in the previous perovskite solar cells was one of the concerns for the industrialization. Sn perovskite solves the disadvantage.  In addition, the theoretical efficiency of the Sn perovskite solar cells is higher than that of Pb perovskite solar cells. The problem is the low efficiency caused by various defects in the lattice and the grain boundary. After taking approaches to decrease the defect density, the efficiency has been enhanced to 14-15% for Pb free Sn perovskite solar cells and 23-24% for SnPb alloyed perovskite solar cells which surpassed the Pb perovskite solar cells with the same inverted structure. These results would be applied to the fabrication of the bottom layers of the perovskite tandem solar cells with the efficiency over 33% which is the theoretical limit of single junction solar cells.</p>