21. Perovskite solar cells have active materials with a crystalline structure identical to the mineral perovskite . 22. There are a few crystal structures, notably the perovskite structure, which exhibit ferroelectric behavior. 23. It has a perovskite -based crystal structure, which has the general form ABO 3. 24. In meteorites it occurs with perovskite , melilite, hibonite, spinel and calcium rich pyroxene. 25. Perovskite cells convert a broader spectrum of sunlight into electricity than conventional silicon-based cells.26. The main advantage of tin-based perovskite solar cells that they are lead-free. 27. They also showed that carrier lifetimes in the mixed perovskite are longer than in the pure iodide. 28. There are a limited number of published studies to address the environmental impacts of perovskite solar cells. 29. The first description of the tolerance factor for perovskite was made by Victor Moritz Goldschmidt in 1926. 30. Perovskite solar cells hold an advantage over traditional silicon solar cells in the simplicity of their processing.
