Investigation of the effect of MAI and PbI2 concentrations on the properties of perovskite solar cells

Here, the effect of perovskites layer quality on the performance of compact-TiO2/mesoporousTiO2/CH3NH3PbI3/carbon solar cells was investigated. Different perovskite layers were prepared by varying concentrations of PbI2 and CH3NH3I, while reaction temperature and dipping time were fixed. The range of concentrations for PbI2 and methylammonium iodide (MAI) were 1-1.4Mand 6-10mgml-1, respectively. Fabricated perovskite layers were first coated by carbon electrodes (5-layer) and then, the champion one was coated by Spiro-OMeTAD (as a hole transport material) and Au-evaporated layer as a cathode (6-layer). Fabricated films were fully characterized by field emission scanning electron microscopy, X-ray diffraction analysis, UV-Vis spectroscopy and photoluminescence spectrum. Photovoltaic properties were measured under AM 1.5. Output currents of 5-layer cells were in the range of 228-476 mu A, of which the highest one was obtained by using 1.2M PbI2 and 8mgml-1 MAI. Ultimately, the maximum power conversion efficiency of 9.1% was obtained with 6-layer cell.