The effect of annealing of organometallic perovskite CH3NH3PbI3 film on its electrical, photoelectric, and optical properties is studied. It was shown that annealing at Та>140 °C leads to the two-phase structure formation consisting of perovskite and lead iodide, the relative content of which depends on the annealing conditions, in particular, on its temperature. The PbI2 formation in the perovskite structure leads to a decrease in the conductivity and photoconductivity of the material. Our studies indicate the possibility of forming planar structures consisting of semiconductor materials with various values of the band gap: 1.6 eV (CH3NH3PbI3) and 2.4 eV (PbI2).
Cubic Perovskite Structure of Black Formamidinium Lead Iodide, α-[HC(NH2)2]PbI3, at 298 K
