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 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 from 1:4 to 3:7.
This work is sponsored by the Air Force Office of Scientific Research, Air Force Material Command, USAF, under Grant No. FA8655-13-1-3018. The authors also acknowledge BRNS, Government of India, for funding the work carried out under this paper. The authors are also grateful to Dr Lesley Hanna of the Experimental Techniques Centre, Brunel University London for fruitful discussions and input.
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