Synthesis and dielectric characterisation of triiodide perovskite methylammonium lead iodide for energy applications

Impedance spectroscopic measurements on spin coated 550 nm thick perovskite films sandwiched between titanium oxide (TiO2) deposited on fluorine doped indium tin oxide (FTO) glass substrates and with a platinum (Pt) counter electrode have been performed to determine the influence of the percentage of PbI2 in methylammonium lead iodide (CH3NH3PbI3) compounds. These compounds with perovskite structure have been synthesized by weaving methylammonium iodide (CH3NH3I) and lead iodide (PbI2) in two different weight ratios of 1:4 and 3:7. The surface grains are found from the scanning electron microscoping images to have become relatively larger with increasing PbI2 content in spincoated perovskite film. Nearly 2% increase in optical band gap has been observed with increasing weight ratio of PbI2 content from1:4 to 3:7 .variou