Effect of non-stoichiometry of initial reagents on morphological and structural properties of perovskites CH(3)NH(3)PbI(3)

The properties of films of organic-inorganic perovskites CH(3)NH(3)PbI(2.98)Cl(0.02) depending on the ratio of starting reagents in solutions (PbI(2):{CH(3)NH(3)I + CH(3)NH(3)Cl}) has been investigated. It was found that the formation of the perovskite structure with the ratio of the initial reagents PbI(2): CH(3)NH(3)I = 1:1 occurs at 70–80 °C, and with the increase of the temperature of thermal treatment to 120 °C, the thermal destruction of the perovskite begins. When the ratio of the starting reagents PbI(2): CH(3)NH(3)I = 1:2, the formation of the perovskite structure occurs through the intermediate compound (CH(3)NH(3))(2)PbI(4), and when the ratio is 1:3—(CH(3)NH(3))(3)PbI(5) and (CH(3)NH(3))(2)PbI(4). Independent on the ratio of the initial components (CH(3)NH(3)I:PbI(2)), the ratio between the content of lead and iodine in the films remains unchanged, that is why a significant difference in the film properties could be explained by the anisotropy of the particle shape, which is consistent with the data of electron microscopy and X-ray diffractometry. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s11671-018-2841-6) contains supplementary material, which is available to authorized users.