Degradation Behavior of Methylammonium Lead Iodide (CH3NH3PbI3) Perovskite Film in Ambient Atmosphere and Device.

[Display omitted] • CH 3 NH 3 PbI 3 perovskite degradation was observed for three days interval until film gets fully degradation. • The Copper iodide (CuI) was employed as hole transport layer for device study. • Phase change, element exclusion, surface changes electrical changes was observed during the degradation. • Degradation based impedance changes observed and discussed. • Degradation behaves differently with device and single layer. Methylammonium lead iodide (MAPbI 3) has attracted more attention due to its promising features appropriate for photovoltaic application, although the material still struggles with instability towards environmental factors. Understanding the degradation mechanism in this material is of immense importance in increasing material stability. This work investigated the degradation process of MAPbI 3 perovskite in an ambient atmosphere with controlled humidity for twelve days at three days interval. The crystallographic structural changes were observed by X-Ray Diffraction (XRD) and analyzed with the support of the Rietveld refinement method. The result shows transition from MAPbI 3 Tetragonal to PbI 2 trigonal by removal of CH 3 NH 3 I, which is evident in X-ray photoelectron spectroscopy (XPS) elemental analysis. UV–Vis spectroscopy and photoluminescence show changes in the band-gap. Scanning electron microscopy (SEM) observes morphological changes and impedance spectroscopy studies electrical behavior. Our study explains the MAPbI 3 structural, optical, morphological, thermal, and electrical behavior changes during degradation in different studies; it is beneficial for a deeper understanding of the degradation mechanism. [ABSTRACT FROM AUTHOR]