Characterization of methylammonium lead iodide (CH3NH3PbI3) perovskite films by time dependent current-voltage (I-V) measurements

In this thesis, film production with MAPbI3 (Methylammonium Lead Iodide) structure, which is used as an optical absorber layer in perovskite solar cells, which is from the third generation organic solar cell family, was carried out. Perovskites show instability depending on the production method and ambient conditions. Within the scope of the thesis, Thermal CVD (Thermal Chemical Vapor Deposition) method was used for the production of perovskite thin films that have completed the chemical reaction process and have a stable structure. Scanning Tunneling Microscope (SEM) was used for the analysis of XRD (X-ray Diffraction) patterns and surface morphology analyzes for the structural characterization of the produced materials. In order to understand the instability mechanism created by different atmospheric conditions on perovskite films, four different stress factors were applied on the materials. These stress factors are laboratory atmosphere, ultraviolet (UV) light application, oxygen (O2) application and deionized water vapor application, respectively. Dark conductivity values were recorded while applying each stress factor, under the stress factor and after the stress factor was removed. In the obtained findings, it was determined that certain stress factors cause electronic defects on the materials. In order to eliminate these defects, heat treatment was applied to the materials and the effect of the heat treatment application on the electronic defects in the materials was determined by conductivity measurements.