Effect of non-stoichiometry of initial reagents on morphological and structural properties of perovskites CH₃NH₃PbI₃.

ABSTRACT: The properties of films of organic-inorganic perovskites CH₃NH₃PbI_2.98Cl_0.02 depending on the ratio of starting reagents in solutions (PbI₂:{CH₃NH₃I?+?CH₃NH₃Cl}) has been investigated. It was found that the formation of the perovskite structure with the ratio of the initial reagents PbI₂: CH₃NH₃I?=?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 PbI₂: CH₃NH₃I?=?1:2, the formation of the perovskite structure occurs through the intermediate compound (CH₃NH₃)₂PbI₄, and when the ratio is 1:3-(CH₃NH₃)₃PbI₅ and (CH₃NH₃)₂PbI₄. Independent on the ratio of the initial components (CH₃NH₃I:PbI₂), 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.

SUBMITTER: Belous A 

PROVIDER: S-EPMC6320708 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature