Abstract
The properties of films of organic-inorganic perovskites CH3NH3PbI2.98Cl0.02 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.
Keywords: Metal halide perovskite, Film, Microstructure, Chemical reaction, Raman spectroscopy

000081

My Library

Available

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