Development and Testing of Operando Degradation Protocols for Perovskite Solar Cells Using Grazing Incidence Wide Angle X-ray Scattering

Abstract

Solar cells based on lead halide perovskites recently made large improvements to device power conversion efficiency through active layer design and device engineering. However, current best practices for improving device performance focus on engineering-based solutions such as encapsulation to try and stabilize devices. The improvement in intrinsic device stability for higher yielding perovskite solar cells has only made marginal gains for commercial application. The goal of making an intrinsically stable solar cell requires a fundamental understanding of the different degradation pathways with a way to measure devices to determine which pathway or combination of pathways causes device failure. Here I design an experimental protocol that can measure performance and structural characteristics of perovskite solar cells in an environmentally controlled chamber. These experiments test full devices while an X-ray beam from a synchrotron source probes the device for structural information. Under different experimental conditions the device degradation is a complex combination of different degradation and healing mechanisms. The main influencing factor in device failure can vary across different measurement protocols and within the same protocols due to minor differences in layer deposition and from defects present within the films. Due to how changes in the experimental environment affects device performance the correlation of data between different measurements is problematic. Therefore, the measurements are gathered simultaneously to increase the accuracy of correlations made between separate data sets. The goal of this thesis is show the preparation and application of an operando chamber at the Canadian Light Source and the analysis of the time resolved correlated data that can be acquired from this experimental setup.