Organic-inorganic hybrid pervoskite solar cells have attracted a lot of interests recently due to its high efficiency (over 20%) and solution based processing. While much research has been done into the general structure of the perovskite material using x-ray and neutron diffraction, and spectroscopy analyses, transmission electron microscopy investigations have not been done extensively, possibly due to the highly beam sensitive nature of the material, making TEM investigations difficult but interesting. It is possible that the crystallinity and defects of the grains forming the photoactive perovskite layers affects the performance of the solar cells, and it is therefore of interest to investigate this further. Perovskite crystals and grains made by several different fabrication methods have been examined, ranging from very fast (gasassisted spin coating) to very slow (single crystal growth from solution) crystal growth rates, and their crystallinities and defects have been compared using TEM and selected area diffraction. Furthermore, photoluminescence was used to study the carrier lifetime of the different crystals as well as to map their photoluminescence intensities. It was found that the crystallinity of the grains is affected by the growth conditions, and that increasing crystal growth rate results in decreased crystallinity and increased crystal defects. This has possible implications for the performance of perovskite solar cells as the defects may hinder the charge generation and/or transport in the material, resulting in lower performance. If the crystallinity and defects can be controlled, it may be possible to further increase the performance of perovskite solar cells.