Electrical properties of organometallic perovskite films

The electrical properties of the films of organometallic perovskites H$_{3}$NH$_{3}$PbBr$_{3}$ and CH$_{3}$NH$_{3}$PbI$_{3}$ were studied. Current–voltage characteristics for the H$_{3}$NH$_{3}$PbBr$_{3}$ and CH$_{3}$NH$_{3}$PbI$_{3}$ samples were measured in a temperature range of 300–80 K, from which the temperature dependences of resistivity $\rho(T)$ having characteristic points of inflection in a range of 160–240 K were determined. The activation energies of charge carriers prior to and after points of inflection were determined. It is assumed that the observed features in the temperature dependences of resistivity (temperature at the points of inflection) correlate with the temperatures of tetragonal-to-orthorhombic phase transitions for two studied organometallic perovskites (H$_{3}$NH$_{3}$PbBr$_{3}$ and CH$_{3}$NH$_{3}$PbI$_{3}$).