Determination of Optical, Electrical, Structural, and Morphological Properties of MAPbI3 Perovskite Films for Photovoltaic Applications

Abstract

Perovskite devices based on methylammonium have been promising in the photovoltaic industry. A major challenge encountered with these devices lies in correlating their processing conditions, microstructure, and the overall photovoltaic performance. In particular, this paper addresses the challenge of accuracy in relating these properties by employing an automated SEM image Python segmentation approach that quantifies grain morphologies. The results derived from the segmentation technique assure reproducibility and bridge the gap between film fabrication, microstructure, and the properties. The resulting films were prepared by two-step spin coating and two-stage thermal annealing procedures, resulting in a planar inverted perovskite with architecture ITO/ PTAA/MAPbI₃/C₆₀ /BCP/Ag.  The fabricated films exhibit a tetragonal structure with high crystallinity, which is characterized by a conspicuous (110) plane. The results display fairly good homogeneity and large grain sizes averaging 212 nm, indicating a wide direct band gap of 1.52eV as displayed by the Tauc plots. The films show values of absorption coefficients exceeding 104 cm^-1. Generally, the resulting device has a high power conversion efficiency of 13.91%, demonstrating that the automated SEM segmentation technique is a powerful tool useful in optimizing perovskite device processing parameters. Insights in this study, therefore, provide information on the enhancement of overall morphology-performance correlation leading to high-quality-film photovoltaic devices.